Fungus Humungous
Teenage Mutant Ninja Turtles (2012 TV Series) episode
Season Code: 210
Episode: 36
Original airdate February 16, 2014
Written by Mark Henry
Supervising Producer Ant Ward
Producers: MacGregor Middleton
Ciro Nieli
Directed by Sebastian Montes
Voice Direction Andrea Romano
Supervising Director  Ciro Nieli
Episode chronology
← Previous Next →
"The Good, The Bad, and Casey Jones" "Metalhead Rewired"

Teenage Mutant Ninja Turtles Season 2
October 12, 2013 - September 27, 2014
List of Teenage Mutant Ninja Turtles episodes


  1. The Mutation Situation
  2. Follow The Leader
  3. Invasion of the Squirrelanoids
  4. Mutagen Man Unleashed
  5. Mikey Gets Shellacne
  6. Target: April O'Neil
  7. Slash and Destroy
  8. The Kraang Conspiracy
  9. The Good, The Bad, and Casey Jones
  10. Fungus Humungous
  11. Metalhead Rewired
  12. Of Rats and Men
  13. The Manhattan Project, Part 1
  14. The Manhattan Project, Part 2
  15. Mazes & Mutants
  16. The Lonely Mutation of Baxter Stockman
  17. Newtralized!
  18. The Wrath of Tiger Claw
  19. Pizza Face
  20. The Legend of the Kuro Kabuto
  21. Plan 10
  22. Vengeance is Mine
  23. A Chinatown Ghost Story
  24. Into Dimension X!
  25. The Invasion, Part 1
  26. The Invasion, Part 2

Season 1Season 2 - Season 3Season 4 - Season 5

"Fungus Humungous" is the tenth episode of the second season of the 2012 TV series, and the thirty-sixth episode overall in the series. It first aired on February 16th 2014.


A fungus mutant spreading through the sewers causes the Turtles, Casey and April to experience their worst fears. Leonardo must face his greatest fear, losing his team, in order to save the city.


Major characters

Minor characters


The episode begins with Casey and April sitting on a random bench in the middle of New York City listening to music. April tells Casey that she enjoys having a true friend who knows about the existence of the Turtles. Casey agrees and responds that four Turtles living underground with a rodent master is something that no one could make up. The two then wait until the coast is clear and decide to go down into the sewer to pay a visit to the Turtles, but when they get down there, an extremely noxious smell (not the sewage) ends up catching their attention. Suddenly, a sewer maintenance man appears out of nowhere and runs right past April and Casey, screaming "SQUIRREL!! GIANT MUTANT SQUIRREL!'' The two then follow the terrified man around a nearby corner, but find that he has completely disappeared. Then, April hears something rather strange and before she knows it, something blows what seems to be a type of powder directly into her face. She then glances at Casey and glimpses that his face looks like a bat's face! Mortified, she walks in the opposite direction and suddenly sees what appears to be her mutated father standing there in her tracks!!!

Casey is utterly bewildered by April's strange behavior – and he quickly goes to inform the Turtles of this (as April is seemingly reluctant to come along with him). Meanwhile, in the lair, Splinter and Leo are in deep meditation. Splinter has no trouble whatsoever in doing so (as per usual), but Leo is having quite a bit of trouble, due to some recent nightmares that he's been having about his brothers being dragged off into pure darkness and him being powerless to help. Splinter tells him that losing one's team is a common fear that almost every single leader must face here and there. Casey then enters the lair and tells all of them of April's very odd attitude. When Casey says that he does not know exactly where he left her, Donnie begins chastising him, but the two (luckily) are quickly able to break up their little squabble... So, the team heads out into the sewers to find April. However, the same thing that stunned April soon stuns Casey as well - and this very same thing provokes his absolute greatest fear as well - rats. And tons of them start appearing in his hallucination and begin engulfing Casey himself, much to his own dismay. This time, it is the Turtles who are utterly baffled. While Casey becomes increasingly frantic, Donnie rounds a corner and spots a still horrified April, who is also still hallucinating that her mutated bat father is there. Donnie tries to calm her down, but to no avail whatsoever. The Turtles then come to the realization that Mutant Mushrooms have been the perpetrators of all this turmoil!

One then appears and attaches itself to Mikey's face, and from that point on, the four brothers do the very best they can to dispose of the little pests, but one manages to spray Raph with the very same stuff that caused Casey and April to become terrified - and thus, Raph does as well. He hallucinates Leo as Chong (the Spy-Roach) and, creating a vow to eliminate the repugnant roach, he quickly jumps into the air and mistakenly is about to harm Leonardo! Leo dodges out of the way, however, and Raph lands hard on the ground. Mikey then wraps his nunchakus around his now extremely mortified brother - and is actually able to contain him for a brief moment.

Back in the lair, Donnie swipes some of the stuff that the mushrooms spewed off of April - and he makes a major yet odd discovery - The stuff that the mushrooms have been affecting April, Casey, and Raph with what are actually toxins that are part of the mushrooms' natural defense mechanisms. But, for some weird reason, they seem to make people experience their worst possible fears... The team then goes back out into the sewers to try and prevent the mushrooms from reaching the numerous city streets. They keep walking until they get to an area where a little 'army' of mushrooms begin attacking them and they spray Mikey. Coughing, he accidentally trips over one of Raph's legs and they both freak out at the sight of one another when they get back up (Raph sees Mikey as Spy-Roach, and Mikey sees Raph as a squirrelanoid).

Then, Donatello is sprayed by the substance and begins hallucinating that April (with a demon-like appearance) mortally hates him and is calling him a freak over and over again. Everyone then rapidly leaves the area, leaving Leo completely abandoned. However, he is sprayed as well. Then, he begins hallucinating that his former favorite character from Space Heroes (Captain Ryan) is slapping him and scolding him because of his utter failures in life - His failure to protect his brothers... He then imagines his own brothers admonishing him about this very failure. He tries to snap out of it, but this does not work. Then, even more mushrooms appear and gather in a single file line and start to slowly surround Leo. Two of them soon fly up and squirt the same substance into his face yet again, which causes him to slip and fall off of a nearby edge. He soon lands in an unknown place, but, luckily, is completely uninjured. He quickly gets himself back up, and sees a gigantic figure standing nearby - This gargantuan mushroom has one huge eye protruding from the center of it's "head" and the creature can also seemingly speak.

It quickly orders all of it's "mushroom spawns" to cause more and more fear within Leo - and sure enough, Leo becomes even more increasingly fearful, frantic, and conscience-stricken. However, he is actually able to snap out of it momentarily and slice many of the attacking mushrooms in half. When he becomes fearful yet again, he instinctively remembers what Master Splinter had told him earlier. Thus, he grabs his two Katanas, presumably destroys the gigantic mushroom by letting a considerable amount of sunlight into the room (using one of the bizarre exploding eyes used by the mushroom), and then snaps out of his trance with relative ease. Meanwhile, the other Turtles, April, and Casey snap out of it as well, but only due to the fact that "Fungus Humungous" was destroyed – and that itself apparently caused a chain reaction, in which all of the other fungi were destroyed as well...

The others soon find Leo lying on the ground, seemingly unconscious, but he quickly wakes up and Raph proceeds to thank him for saving every single one of their lives - however he did it exactly. They then head back to the lair and joyously discuss their triumph. Leo tells his Master Splinter about everything that he did, which causes his sensei to ask him if he mastered his fear. Leo responds that he just faced it and Splinter tells him that that is what makes him a great leader. Meanwhile, Mikey brings out a 'victory Antonio pizza', with pepperoni, anchovies, and extra mushrooms - which obviously disgusts all of them and they leave the area. However, Mikey has no concern over this and lifts up a slice to examine it, noticing that there is a mushroom on it that is MOVING (or dancing).


  • The Mushroom dancing around Leo to the tune of the "Nutcracker Suite" is a reference to Walt Disney's 1940 animated film, Fantasia.
  • Leo has the same general fear as his other incarnations, failure since he fears of losing his brothers, and there's nothing he can do about it.
  • Mikey makes a Super Mario Bros. reference, as he jumped on the top of the mutant mushrooms and called it "Super Mikey Brothers".
  • Raph screaming "I'll bury you, cockroach!" is likely a reference to the movie Scarface where Tony Montana retorts in anger what he would do to Gaspar Gomez and the Diaz Brothers.
  • April's worst fear is bats (her dad), Casey's fear is rats, Mikey's fear is the Squirrelanoids, Donnie's fear is April's rejection, Raph's fear is roaches (the Spy-Roach) and Leo's fear is being a bad leader and the loss of his loved ones.
  • In one scene, the Wilhelm scream can be heard in the TV.
  • Although Fungus Humungous was destroyed in the episode, one of the producers of the show said they wanted to bring him back in the future.[citation needed]


April: So, what's with the mask? I mean, it's not like the turtles don't know who you are.
Casey: Same reason people have worn masks throughout history… Cause it looks cool.

Leonardo: (failing to meditate properly) Ugh…
Splinter: Leonardo…?
Leonardo: (screams in alarm) Oh, sorry Sensei… Can't seem to focus.
Splinter: I noticed. What is it that troubles you, my son?
Leonardo: I keep having the same nightmare, Sensei. Every night. I let the team down… They're dragged off into darkness, and I'm powerless to help.
Splinter: This is not uncommon. All leaders must face the fear of losing their team. I face this every time you and your brothers leave the lair.

Casey: (runs into lair, panting) Guys! April! Sewers! Hurry!
Raphael: Casey, what's wrong?
Leonardo: Are the Foot bots back?
Casey: W-we were on our way here, and next thing I know April starts acting freaked out, then runs off! She's gone!
Donatello: Wait, wait… You just LOST April!?
Michelangelo: Relax! I'm sure there's a logical explanation. Like she was eaten by a giant sewer snake, or something.
Donatello: LET'S GO!

Casey: (coughing) That was HIDEOUS!
Raphael: Dude, you put your nose in a New York City sewer. What'd you expect?

Raphael: What is THAT?
Michelangelo: It's a mushroom! With feet! Aw, it's so cute! (mushroom attaches itself to his face) AAH! GET IT OFF OF ME! GET IT OFF OF ME!

April: BATS! Get away from me!
Casey: THE RATS!
Michelangelo: What is going OOONNN?

Leonardo: Raphael, are you ok?
Raphael: (sees Leo as Chong) No, it's YOU! Anybody but YOU! Keep away from me!
Leonardo: Raph? Take it easy, man…
Raphael: That's it! If you won't stay away, I'll splatter ya!

Michelangelo: C'mon, dude! STOPPIT! Calm down… (singing voice) Breathe with meeeee!

Leonardo: What is going on here?
Donatello: Fungus!
Michelangelo: Language, please! There's a lady present.

Donatello: April and Raph have been exposed to toxins found in certain types of fungi. The mushroom must produce it as some kind of defense mechanism.
Leonardo: Defense against what? Being stir-fried?
Raphael: (hallucinating them as giant cockroaches) I'm freaking out! I'm freaking out! I'M FREAKING OUT!

Michelangelo: (stomping mushrooms) Check it out! Super Mikey Brothers!

Raphael: (seeing Mikey as a cockroach) COCKROACH!!
Michelangelo: (seeing Raph as a Squirrelanoid) SQUIRRELANOID!!

Donatello: (coughing) April! We need to get out of here! Take my hand!
Hallucination-April: Don't touch me! Get away from me! You make me sick! Mutant! WEIRDO!
Donatello: April… What's wrong with you?
Hallucination-April: You nerdy, three-fingered freak, I hate you! You mutated my father! I NEVER WANT TO SEE YOU AGAIN!

Leonardo: Everybody's gone… It's my fault! I failed them! It's all my fault!
Hallucination-Captain Ryan: It's your fault, Cadet Leonardo! You blew it! What kind of a leader are you? Are you a man, or a turtle, or a zero?

Leonardo: Ugh… Where am I?
Hallucination-Michelangelo: You let us down, bro!
Hallucination-Donatello: You did this!
Hallucination-Raphael: It's your fault, Leo!
Leonardo: NO! No! C'mon, fight your fear, Leo! Get your head straight… FIGHT IT!

Fungus Humongous: Taste fear. Feed. More fear. Stronger. Spread my spawn.


Leonardo: I can't do it… Failure… I'm a failure. I let the guys down. I-I let them down, I… (spots katana)
Flashback-Splinter: All leaders must face the fear of losing their team.
Leonardo: NO! No, I can't give up! Your spores won't work on me! I face my fear every single day!

Leonardo: So that's YOUR fear… Sunlight!

Michelangelo: Leo? Speak to me bro… Do you need mouth-to-mouth?
Leonardo: (covers Mikey's mouth) Absolutely… not. You're all… ok?
Raphael: Well, whatever you did, you saved us. Thanks, man.
Leonardo: No problem.



Fungus Humungous (episode)/Transcript