strategy cleansing

Those failed experiments look incredibly unstable!
Everything about this operation is incredibly unnatural!

―Commander dialogue on Wave 20 (Intermediate)

Description

The Failed Experiment is an enemy that appears in Intermediate mode. It has a high amount of health, higher than every enemy that appeared before it, and walks at an above average speed. Additionally, it always spawns with the slime attribute, making it spawn a Slime upon death.

Appearance

The Failed Experiment is a humanoid with lower limbs in its rig. In place of legs, it has a tail made of a translucent green goo coming out of its damaged torso, with a large swaying spine attached to it. It has teal tumors and green veins across its body, as well as a line of stitches on its head. It is missing part of its right forearm, which reveals a large bone.

It has a death animation, where its arms will give out from under itself, making it fall to its stomach.

Strategy

Do note that all freezing and stunning towers will only stall the Failed Experiment for a shorter amount of time, due to its large size.

Gallery

Thumbnails

Failed Experiment on the game thumbnail.

Development Images

Failed Experiment on a development gif.

Update History

3 May 2024
- Failed Experiment added.
11 September 2024
- Health increased from 2,000 to 2,500.
- Speed increased (3.5 to 4).
- Now is a boss enemy when it first spawns.

Notes

↑ Only the first Failed Experiment is a boss enemy.

Intermediate
Previous Debut	Current Debut	Next Debut
Speedy Boss Wave 18	Hidden Boss & Failed Experiment Wave 20	Breaker4 Wave 25

Normal Gamemode Enemies
Easy Mode	Normal • Speedy • Slow • Normal Boss • Hidden • Breaker2 • Breaker • Necromancer • Skeleton • Armored • Slow Boss • Enraged • Breaker3 • Brute
Casual Mode	Normal • Speedy • Slow • Normal Boss • Hidden • Enraged • Armored • Breaker2 • Breaker • Necromancer • Skeleton • Slow Boss • Hidden Boss • Hazmat • Speedy Boss • Breaker4 • Breaker3 • Grave Digger
Intermediate Mode	Normal • Speedy • Slow • Normal Boss • Abnormal • Quick • Heavy • Elite Abnormal • Hidden • Breaker2 • Breaker • Bolt • Reaver • Ghoul • Boomer • Hazmat • Living Experiment • Speedy Boss • Slime • Breaker4 • Breaker3 • Elite Hazmat • Hidden Boss • Failed Experiment • Giant Boss • Patient Zero
Molten Mode	Abnormal • Quick • Heavy • Elite Abnormal • Molten • Corpse • Molten Demon • Breaker3 • Breaker2 • Breaker • Molten Golem • Elite Hazmat • Hidden Boss • Molten Necromancer • Elite Boomer • Molten Hound • Molten Mech • Bulwark • Breaker4 • Elite Molten • Molten Executioner • Tanker • Molten Summoner • Molten Titan • Molten Warlord
Fallen Mode	Abnormal • Quick • Fallen Skeleton • Fallen Dreg • Corpse • Fallen Squire • Breaker2 • Breaker • Fallen Soul • Fallen • Fallen Giant • Fallen Hazmat • Possessed Armor • Fallen Necromancer • Corrupted Fallen • Fallen Seraph • Fallen Jester • Necrotic Skeleton • Breaker4 • Breaker3 • Fallen Rusher • Fallen Hero • Fallen Shield • Fallen Summoner • Fallen Angel • Fallen Honor Guard • Fallen Tank • Fallen Guardian • Fallen King • Warden • Awakened Fallen King
Frost Mode	Frozen • Snowy • Snowman • Frostmite • Snow Golem • Cold Mist • Frost Mystery • Snow Minion • Crying Angel • Yeti • Packed Ice • Unstable Ice • Frost Invader • Frost Undead • Blizzard Wizard • Frost Hunter • Frostbane • Frost Ravager • Deep Freeze • Shivergeist • Frost Mage • Mega Frost Mystery • Frost Necromancer • Frost Champion • Jack Frost • Frost Hero • Frost Spirit • Ice Beacon
Challenge Trials	Abnormal • Quick • Heavy • Elite Abnormal • Breaker2 • Breaker • Armored • Necromancer • Skeleton • Bolt • Living Experiment • Elite Hazmat • Speedy Boss • Circuit • Giant Boss • Necrotic Skeleton • Breaker4 • Breaker3 • Tanker • Necromancer King • Cursed Skeleton • Fallen Tank • Brute • Grave Digger • Enraged • Normal Boss • Hazmat • Warden • Champion Templar
Hardcore Mode	Odd • Swift • Hefty • Mandrake • Phantom • Balloon • Lead • Elite Lead • Mystery • Blighted • Cursed Skeleton • Voidling • Void Reaper • Elite Phantom • Mandragora • Void Rusher • Void Pike • Void Titan • Void Floater • Elite Mystery • Void Brute • Unknown Small • Elite Void Rusher • Nightshade • Void Keeper • Soul • Slow King • Void Cultist • Healing Beacon • Speedy King • Vindicator • Heavy Voidling • Elite Soul • Unknown Boss • Void Knight • Void Trickster • Void Portal • Void Swordmaster • Void Guardian • Void Reaver • Void Eye
Voidcore Mode	Odd • Swift • Hefty • Cursed Skeleton • Phantom • Balloon • Lead • Elite Lead • Mystery • Blighted • Mandrake • Voidling • Elite Phantom • Void Reaper • Void Floater • Void Rusher • Void Pike • Void Titan • Mandragora • Elite Mystery • Void Brute • Void Keeper • Unknown Small • Elite Void Rusher • Slow King • Speedy King • Crystalian • Soul • Elite Soul • Void Trickster • Void Portal • Nightshade • Vindicator • Unknown Boss • Void Cultist • Healing Beacon • Soul Stealer • Void Eye • Heavy Voidling • Void Knight • Void Swordmaster • Void Guardian • Void Reaver • Void Caster

Special & PVP Enemies
Basic Arena	Normal • Quick • Speedy • Slow • Normal Boss • Hidden • Breaker2 • Breaker • Necromancer • Skeleton • Armored • Hazmat • Slow Boss • Hidden Boss • Enraged • Breaker4 • Breaker3 • Speedy Boss • Brute • Champion Templar
Molten Arena	Normal • Quick • Speedy • Slow • Elite Abnormal • Hidden • Breaker2 • Breaker • Enraged • Armored • Molten • Reaver • Necromancer • Skeleton • Molten Hazmat • Living Experiment • Hazmat • Hidden Boss • Molten Mech • Molten Necromancer • Molten Demon • Molten Golem • Breaker4 • Breaker3 • Failed Experiment • Slime • Molten Titan • Corpse • Champion Templar
Fallen Arena	Abnormal • Quick • Heavy • Fallen Squire • Fallen Soul • Fallen Hazmat • Fallen • Fallen Giant • Breaker2 • Breaker • Fallen Necromancer • Fallen Skeleton • Possessed Armor • Fallen Hero • Fallen Tank • Fallen Shield • Fallen Guardian • Breaker4 • Breaker3 • Champion Templar
Polluted Wasteland II	Wastewalker • Wasterunner • Hazardous • Super Mutant • Breaker2 • Breaker • Lurker • Necromancer • Skeleton • Toxic • Corpse • Splitter • Split • Fleshling • Amalgamation • Circuit • Breaker4 • Breaker3 • Mutagenic Blight • Rusher • Super Slime • Goo • Abomination • Super Toxic • Warden • Necromancer King • Cursed Skeleton • Nuclear Guardian • Nuclear Monster
Badlands II	Abnormal • Quick • Heavy • Skeleton • Elite Abnormal • Corpse • Fallen Skeleton • Breaker2 • Breaker • Husk • Giant Skeleton • Necromancer • Withered • Undead Miner • Breaker3 • Breaker4 • Hazard • Tank • Breaker4 • Breaker3 • Necrotic Skeleton • Tanker • Cavalry • Conjurer • Gunslinger
Pizza Party	Abnormal • Quick • Heavy • Ghost • Scout • Breaker2 • Breaker • Citizen Plush • Shotgunner • Marionette • Clown • Knight • Monkey • Cobalt Guard • Commander • Sock Puppet • Balloon Kid • Minigunner • Mimic Umbra • Corpse • Breaker4 • Breaker3 • Voodoo Doll • Executioner • Reaper • Demon • Sin • Wox the Fox
Tutorial	Normal • Speedy • Slow • Hidden
Headache Headquarters	Toilet • Streamer • Chad • Metal Toilet • Ninja Toilet • Png Bot2 • Png Bot • Brick Man • Armored Toilet • Megatron Toilet • Pro Streamer • Arrow • Speedy Boss • Png Bot4 • Png Bot3 • Brute

Sandbox Exclusive Enemies
Legacy Molten Mode	Normal • Speedy • Slow • Normal Boss • Hidden • Mystery • Necromancer • Molten • Slow Boss • Hidden Boss • Shock • Speedy Boss • Mystery Boss • Mystery Summoner • Molten Titan • Molten Boss
Golden Mode	Abnormal • Quick • Heavy • Abnormal Boss • Shadow • Mystery • Dark Necromancer • Golden • Chained Boss • Shadow Boss • Charge • Tank • Mystery Boss • Boomer • Summoner Boss • 24 Karat • Gold Guard • Gold Titan
Legacy Fallen Mode	Abnormal • Quick • Heavy • Abnormal Boss • Shadow • Mystery • Dark Necromancer • Fallen • Giant Boss • Shadow Boss • Glitch • Hazard • Tank • Mystery Boss • Boomer • Templar • Summoner Boss • Error • Fallen Hero • Fallen Guardian • Fallen King
Brain Rot	Toilet • Streamer • Chad • Metal Toilet • Ninja Toilet • Png Bot2 • Png Bot • Brick Man • Armored Toilet • Megatron Toilet • Pro Streamer • Arrow • Png Bot4 • Png Bot3 • Toilet Boss
Other	Slime • Dummy Boss • Imposter • Invisible • Lead • Lead Boss • Mega Slow • Fallen Reaper • Fallen Soul • Fallen Rusher • Fallen Titan • Lead Balloon • Slow King • Circuit • Speedy King • Warden • Health Cultist • Soul Stealer • Soul Boss • Necromancer Boss • Fallen Swordmaster • Unknown • Vindicator • Void Reaver

Event Enemies
The Heights	Slow • Knight • Speedy • Normal • Boomer 1 • Stone Viking • Hidden • Normal Boss • Necromancer • Crystalite • Mystery • Brute • Fallen Hero • Swordmaster • Slow Boss
Area 51	Alien • Strong Alien • Zoomer • Hidden Zoomer • Lawnmower • UFO • Raider 1 • Raider 2 • Raider Boss
Nightmare Carnival	Mummy • Strong Mummy • Scarecrow • Demon • Ghost • Vampire • Bat • Witch • Reaper • Clown • Frankenstein • Swamp Thing • Jaxe • Jack O' Bot
Village of Despair	Frozen • Snowman • Gingerbread • Burnt Gingerbread • Deep Freeze • Papa Bread • Present • Yeti • Frost Tank • Frost Hero • Krampus
Eggy Island	Zombegg • Sugrawr • Eggsplosive • Hunter • Bunny • Sir Hopsalot • Beehive • Grizzly • Ducky D00M
Trick or Threat Town	Undead • Mummy • Bones • Ghost • Buried • Reanimated • Witch • Slime • Goo • Reaper • Hallow Bones • Vampire • Bat • Hallow Guard • Lord Sinister
Outpost 32 (Frost Invasion)	Snowy • Frozen • Cold Mist • Packed Ice • Frost Mystery • Snow Golem • Snow Minion • Unstable Ice • Deep Freeze • Frost Invader • Frost Ravager • Crying Angel • Frost Necromancer • Frost Hero • Frost Spirit
Cyber City	Normal • Speedy • Slow • Normal Boss • Hidden • Fey Yoshida
Solar Eclipse Event	Rotfield	Undead • Mummy • Bones • Scarecrow • Jaxe
	Foggy Forest	Shroogma • Overgrowth • Ghost • Wraith • Ent • Werewolf • Swamp Monster
	Tower Outskirts	Pike • Knight • Ghost • Cobalt Guard • Vampire • Bat • Wraith • Zombie Horse • Ent • Ghost Knight • Werewolf • Cursed Guard • Cursed Knight • Solar Shard • Lunar Shard • Dust • Penumbras
	Totality Tower	Pike • Knight • Clanker • Wraith • Cobalt Guard • Lunar Shard • Dust • Vampire • Bat • Solar Shard • Headless Jaxe • Mega Clanker • Ghost Knight • Cursed Guard • Cursed Horse • Flare • Lunar Shield • Solar Servant • Lunar Servant • The Umbra
D00M's Revenge	Ducky • Cool Ducky • Fat Ducky • Spy Ducky • Mother Ducky • Cart • Eggroll • Flying Ducky • P3NGU • Operator Ducky • Agent Ducky • Explosive Ducky • Evil Ducky • Long Ducky • Ducky Unit • Ducky D00M
Cold Ambush	Basic Elf • Speedy Elf • Gingerbread • Snowman • Snow Golem • Tough Cookie • Ripped Elf • Present3 • Present2 • Present • Sleigh • Cookie Guard • Bomber Elf • Evil Elf • Builder Elf • Toy Soldier • Gatekeeper • Papa Bread • Mecha-claus
Lunar Overture Event	A Dark Tale	Pumpkid • Overgrowth • Ghost • Scarecrow • Swamper • Citizen Plush • Knight • Cobalt Guard • Executioner
	The Haunted Past	Pumpkid • Skeleton • Mummy • Ghost • Witch • Scarecrow • Giant Skeleton • Frankenstein • Clown • Demon • Sin • Hallow Guard • Werewolf • Reaper • Jack-o-Bot
	The Great Finale	Actor1 • Citizen Plush • Knight • Actor2 • Cobalt Guard • Voodo Doll • Marionette • Executioner • Sock Puppet • Actor3 • Left Hand • Right Hand
Krampus Frosthold	Basic Elf • Speedy Elf • Present • Bomber Elf • Snow Golem • Snowman • Gingerbread • Ripped Elf • Snowy • Frozen • Packed Ice • Crying Angel • Present2 • Tough Cookie • Cold Mist • Cookie Guard • Gatekeeper • Present3 • Papa Bread • Builder Elf • Toy Soldier • Sleigh • Evil Elf • Krampus
Huevous Hunt	Korblox Seeker • Korblox Guard • Korblox Undead • Korblox Soul • Korblox Warrior • Redcliff Traitor • Korblox General • Korblox Deathwalker
The Classic Event	Classic Candy Cane Lane	Normal • Slow • Speedy • Hidden • Normal Boss • Breaker2 • Breaker • Redcliff Traitor • Slime • Slow Boss • Breaker4 • Breaker3 • Necromancer • Skeleton • Grave Digger
	Classic Winter	Korblox Seeker • Korblox Guard • Korblox Undead • Korblox Soul • Korblox Warrior • Breaker2 • Breaker • Redcliff Traitor • Slime • Necromancer • Skeleton • Korblox General • Breaker4 • Breaker3 • Korblox Deathwalker
	Classic Forest Camp	Speedy • Slow • Normal • Hidden • Normal Boss • Breaker2 • Breaker • Hidden Boss • Necromancer • Breaker4 • Breaker3 • Slow Boss • Slime • Grave Digger
	Classic Island Chaos	Korblox Guard • Korblox Seeker • Korblox Undead • Korblox Warrior • Korblox Soul • Necromancer • Skeleton • Slime • Redcliff Traitor • Korblox General • Breaker4 • Breaker3 • Breaker2 • Breaker • Korblox Deathwalker
	Classic Castle	Slow • Normal • Korblox Guard • Korblox Undead • Normal Boss • Korblox Seeker • Breaker2 • Breaker • Korblox Soul • Korblox Warrior • Hidden Boss • Hidden • Necromancer • Skeleton • Korblox General • Redcliff Traitor • Breaker4 • Breaker3 • Slow Boss • Korblox Deathwalker • Grave Digger • Fallen King • Fallen Guardian
Hexscape Event	Failed Gateway	Quick Pawn • Pawn • Brain Bound • Neuro Runner • Mind Shackled • Synaptic • Titus
	The Nightmare Realm	Hex Spawn • Hex Minion • Hex Wraith • Hex Revenant • Forsaken Skull • Hex Mimic • Hex Corpse • Upper Body • Rotting Terror • Blight Walker • Conjurer • Nightmarish Hulk • Hex's Maw • Conserver
	Containment	Hex Spawn • Hex Minion • Hex Wraith • Hex Revenant • Hex Corpse • Upper Body • Forsaken Skull • Hex Mimic • Blight Walker • Rotting Terror • Cursed Horror • Conjurer • Enigma • Eclipsed • Hex Drako • Corrupted Titus • Brain Bound • Neuro Runner • Nightmarish Hulk • Hex Weaver • Hex's Maw • Corrupted Conserver • Withered • Reaper • Primordial Drakobloxxer • Unknown Boss • Unknown Small
Pls Donate	Noob • Guest • Troll • Trader • Dev • Cat • Breaker2 • Breaker • Slime • Necromancer • Skeleton • Alien • Breaker4 • Breaker3 • UFO • Corrupted Haz3mn
Outpost 32 (Operation I.C.E)	Snowy • Frozen • Siege Engine • Packed Ice • Snow Minion • Snow Golem • Snowman • Cold Mist • Deep Freeze • Frost Hunter • Unstable Ice • Crying Angel • Frost Mystery • Frost Invader • Frost Mage • Frost Ravager • Frost Necromancer • Frost Undead • Frost Hero • Frost Spirit • Ice Beacon
Korblox Temple	Korblox Seeker • Korblox Guard • Korblox Undead • Korblox Soul • Korblox Warrior • Redcliff Traitor • Fallen • Korblox General • Fallen Necromancer • Fallen Skeleton • Corpse • Korblox Necromancer • Fallen Honor Guard • Korblox Deathwalker
Bathroom Approach	Ducky • Cool Ducky • Fat Ducky • Mother Ducky • Eggroll 1 • Eggroll 2 • Eggroll 3 • Agent Ducky • Spy Ducky • Flying Ducky • Evil Ducky • Explosive Ducky • Grandmother Ducky • Aged Eggroll 1 • Aged Eggroll 2 • Aged Eggroll 3 • Aged Eggroll 1 • Corpse • Chunky Ducky • Long Ducky • Elite Ducky • Operator Ducky • Missile Ducky • P3NGU • Ducky Unit • Mega Ducky • Ducky D00M III • Super Soldier Ducky • Nerd Ducky
Sk8 P4rk	Noob	Normal • Speedy • Slow • Normal Boss • Breaker2 • Breaker • Necromancer • Skeleton • Bolt • Speedy Boss • Slow Boss • Brute
	Pro	Speedy • Normal • Slow • Ghoul • Enraged • Armored • Breaker2 • Breaker • Reaver • Necromancer • Skeleton • Living Experiment • Hazmat • Failed Experiment • Slime • Patient Zero • Giant Boss
	Master	Abnormal • Quick • Heavy • Elite Abnormal • Breaker2 • Breaker • Molten • Corpse • Molten Golem • Elite Hazmat • Molten Necromancer • Molten Demon • Molten Hound • Breaker4 • Breaker3 • Molten Mech • Bulwark • Tanker • Elite Molten • Molten Executioner • Molten Summoner • Molten Warlord
	Extreme	Abnormal • Quick • Fallen Dreg • Corpse • Fallen Squire • Breaker2 • Breaker • Fallen • Fallen Giant • Fallen Hazmat • Possessed Armor • Fallen Necromancer • Fallen Skeleton • Corrupted Fallen • Fallen Hero • Fallen Shield • Breaker4 • Breaker3 • Fallen Rusher • Fallen Jester • Fallen Tank • Fallen Guardian • Fallen Honor Guard • Fallen Summoner • Necrotic Skeleton • Fallen King
Halloween 2025 Live Events	Nulling • Corrupted Wraith • Hidden • Breaker2 • Breaker • Corrupted Terror • Necromancer • Skeleton • Null Beast • Corrupted Horror • Corrupted Blight Walker • Hidden Boss • Eclipsed • Corpse • Breaker4 • Breaker3 • Executioner • Actor1 • Actor2 • Actor3 • Enigma • Unknown Boss • Unknown Small • Corrupted Conserver • Mechanical Rot
Null & Void Event	Outpost 16	Nulling • Null Runner • Null Dredge • Null Scout • Null Crook Boss • Null Goon • Lost Glitch • Null Freezer • Null Beast • Null Warden • Null Pyromancer • Null Commander • Null Missile APC
	Banlands	Null Runner • Nulling • Null Dredge • Null Shrieker • Null Scout • Lost Glitch • Null Crook Boss • Null Goon • Null Freezer • Null Medic • Null Electroshocker • Null Beast • Null Warden • Null Pyromancer • Null Guardian • Null Guardian Clone
	Blind Faith	Null Scout • Null Dredge • Lost Glitch • Null Runner • Nulling • Null Goon • Null Freezer • Null Shrieker • Null Crook Boss • Null Engineer • Null Sentry • Null Pyromancer • Null Warden • Null Pursuit • Null Electroshocker • Null Medic • Kronus • Null Beast • Null Brawler • Null Accelerator • Skeleton • Giant Skeleton • Executioner Skeleton • Hallow Guard • Null Necromancer • Gravestone • Rift Walker
The Narratorium	Attendee • Fanatic • Sack Noob • Builder • Extra B • Extra A • Stunt Man • Stunt Man Double • Spectator • Spotlight • Security • Spindling • Stereo Man • Performer • Extra D • Extra C • Dancer • Projector • Producer • Actor1 • Actor2 • Actor3 • Painter • Narrator • MiniHand
Backyard Legends Event	Backyard Beginnings	Soccer Ball • Cleats • Boombox • Whistle • Soccer Head • Sports Drink • Duffle Bag • Corpse • Referee
	Competition Court	Soccer Ball • Cleats • Boombox • Corpse • Whistle • Soccer Head • Sports Drink • Duffle Bag • Referee • Soccer Speedy • Crowd Pleaser • Decoy • Soccer Goal
	Victory Field	Cleats • Soccer Ball • Boombox • Whistle • Soccer Head • Corpse • Sports Drink • Duffle Bag • Referee • Crowd Pleaser • Decoy • Soccer Goal • Goal Keeper • Felipe
Halloween 2026 Live Events	Solar Shard • Corrupted Wraith • Corrupted Revenant • Cobalt Guard • Lunar Shard • Corrupted Terror • Necromancer • Skeleton • Corrupted Blight Walker • Null Electroshocker • Corrupted Horror • Null Engineer • Null Sentry • Voidling • Nightshade • Blighted • Elite Mystery • Elite Phantom • Void Floater • Void Reaper • Mandrake • Hefty • Odd • Swift • Void Titan • Actor2 • Actor3 • Actor1 • Enigma • Unknown Boss • Unknown Small • Big Titus • Null Accelerator • Void Portal • Void Brute
Solar Requiem Event	Sorrowful Remains	Dust • Lunar Shard • Solar Shard • Unstable Core • Huntress • Cobalt Guard • Meteorite • Trailblazer • Lunar Titan • Penumbras
	Nightmare Flash	Lunar Shard • Dust • Solar Shard • Cobalt Guard • Huntress • Unstable Core • Astral Spore • Cherub • Trailblazer • Meteorite • Comet • Moon Shade • Lunar Titan • Echo of Resentment
	Poor Recollection	Solar Shard • Lunar Shard • Dust • Cherub • Astral Spore • Meteorite • Comet • Cobalt Guard • Black Hole • Huntress • Unstable Core • Lunar Titan • Artemis • Moon Shade • Trailblazer • Echo of Guilt
	Totality Tower	Dust • Lunar Shard • Solar Shard • Cobalt Guard • Unstable Core • Comet • Cherub • Artemis • Meteorite • Huntress • Black Hole • Lunar Titan • Moon Shade • Echo of Grief • Trailblazer • Icarus • Lunar Servant • Solar Servant • Lunar Shield • The Umbra

Legacy Enemies
Replaced	Blighted • Boomer 1 • Necromancer 2 • Mystery 2 • Gravekeeper • Super Mystery • Ultra Mystery • Uber Mystery • Ninja • Frost Hero • Strong
Pre-MEGA	Carrier • Swarm • Tank 2 • Boomer 2 • Controlled • Shrike Crystal • Rusted • Witch Doctor • Tombstone • Frozen • Deep Freeze • Frost Hero
Polluted Wasteland	Radioactive • Wasted Boss • Amalgamation • Rusher • Splitter • Split • Nuclear Fallen King
Hidden Wave (Legacy)	Glitched Giant • Bug • Bruh • SCT • Jaxe • Mechanical Rot • Frost Hero • Developer 1 • Developer 2 • Developer 3 • Creator • A • B • C
Other	Void • First Form

[1] Only the first Failed Experiment is a boss enemy.

[1]