Side character shown being mutated. He's in silhouette, but you can still hear him screaming, see his body gain new appendages, etc. Later he splits his legs apart and you can see his bones inside.
No it’s not used, however there is a joke in season one where Michelangelo, to Raphael, goes ‘You just can’t admit that you were the r word’ and everyone looks at him, then he finishes, ‘(w)rong?’ Having spelt the word ‘wrong’ incorrectly in his head, making it seem like he was about to call Raphael a slur
Karai, who is shown as Shredder’s daughter, is eventually revealed to have been Splinter’s child, who Shredder had abducted the night that Tang Shen died
Karai is shown as a baby. There is an episode dedicated to the turtles as babies. We are also shown the turtles as toddlers on different occasions , if that’s also uncomfortable for you.
Splinter occasionally smacks the turtles over the head as discipline and "nerve pinches" Raph once to stop him from yelling. The turtles occasionally hurt each other for comedic purposes
In season 4, Shredder is mutated, and keeps wanting more mutagen to sustain himself. This can be seen as addiction and substance abuse, especially when the other villains keep trying to intervene and tell him no. (This is copy pasted from another answer I made)
In season 4, Shredder is mutated, and keeps wanting more mutagen to sustain himself. This can be seen as addiction and substance abuse, especially when the other villains keep trying to intervene and tell him no.
A cat is accidentally mutated but survives and is turned into a live cat-shaped pile of ice-cream. She is loved and treated well by the main characters, and so are other cats in the show
I’d like to say technically? In season 5, a creature called the demodragon is summoned by cultists and a few episodes later he falls into a portal where he presumably would die.
In season one, episode three a man is mutated into a giant spider. There's another episode in season five where the turtles are in another world and encounter a spider-like creature that took the form of a friend of one of the characters.
There is a villain who is mutated into a fly-human hybrid. And in season one, episode eighteen, Raph is forced to face his fear when a cockroach is mutated. In season one, episode twenty-three, a parasitic wasp is the main enemy, and it brainwashes three of the turtles into taking care of its young and then allowing themselves to be eaten by the babies [they survive]. And in season four, episode twelve, the turtles end up on an alien planet with bug-like creatures. And in season four, episode seventeen, Raph again has to face his fear of bugs as they face a bunch of mutated bug enemies.
In season 4, Splinter is stuck in this large chasm and a recurring character, The Rat King, is down there as well, trying to convince Splinter to give in to animalistic urges and nearly gets him to cannibalise one of the many rats that are down there with them.
In season four, episode twenty-four, a villain is fighting against his childhood friend. The friend cuts off his arm. It's not bloody, but you see his severed arm, see the turtle's shocked reactions, and hear his screams as he clutches where his arm used to be.
Casey is missing several teeth, implied to be lost during hockey games. In an episode Casey falls from a height and sits up, checking his mouth and saying ‘I think I lost another tooth’. In an episode, Mikey’s teeth fall out in a comedic light after they arrive home to the lair, this isn’t permanent and was only done for the joke of it.
Multiple scenes. In one of them, April is kidnapped and strapped to a table by the Kraang, who drive a needle-tipped device close to her face to "extract a DNA sample". When she suggest a less painful alternative, they reply that the painful way is more entertaining. She is rescued before anything happens
At one point in season 4, Donatello, who is a teenager, is exploded into his individual atoms and spread across New York. He is resurrected the same episode.
It's mentioned later on that April's mom died. And in the end of season three [SPOILER ALERT] Splinter is killed by Shredder, but the turtles manage to change the timeline and save him. Near the end of [SPOILER ALERT] season four, Splinter actually dies this time, killed by Shredder.
Raph gets motion sickness/space sickness quite a few times during season 4. In one episode he vomits in zero G and the vomit visibly lands on Donnie when gravity is restored (it's bright pink and doesn't look realistic but still) Raph is also shown feeling nauseous and gagging throughout the season
A lot of screaming from injuries, occasional bone cracking/crushing sounds.
Example, in season 4 when Splinter is in a chasm, he breaks his leg and not only has to reset it himself which you fully hear the aftermath of that, but it also ends up being stomped later which you also fully hear, bone crunching and screams of pain.
There's one episode in season two where Mikey needs to make an antidote for his brothers, who are brainwashed by a parasitic wasp. He used a needle to inject the antidote into himself and his brothers.
Karai ends up in a hospital at some point and we see her in a hospital bed with bandages and injuries.
Casey and Shinigami are dropped off at the front of a hospital to await being taken in after sustaining injuries in a fight.
Implied for Leo following the death of Master Splinter, often hallucinating that he is there with them and talking to him for advice. The first time this happens, he is in the woods surrounded by falling petals which I personally think solidifies it as a hallucination rather than spiritual, as we were never shown any pink flowers in those woods before that point.
Also implied for Donnie, after he is kidnapped by Don Vizioso in season 4, then tries to get revenge on him in season 5 before stopping himself from murdering him out of fear of his own anger.
Possibly implied for Raphael, he has a huge phobia of bugs but in an episode where he has to fight bugs, he starts hallucinating horrifying scenes and this could possibly be trauma related rather than just a simple phobia given how severe the visions were and how they left him afterwards.
Mikey once makes a joke about Raph being "the r-word". After a second of his brothers' shocked reactions, he clarifies, "wrong", as they facepalm and shake their heads. It's played as a joke about Mikey being bad at spelling
Leonardo has romantic feelings for Karai, who is the biological daughter of his adoptive father. There are hints they may be romantically involved, even after she has been referred to- and accepted as their sister.
The Mutant Apocalypse arc ends on a pretty bittersweet note. Although the Turtles have finally reunited and can spend the rest of their days in peace, that still doesn't distract from the fact that the storyline takes place in a post-apocalyptic world where everyone they know is dead.
Whilst blood and gore is never shown, some mutations on the show are quite grotesque and fall under the body horror category, which can be disturbing for some viewers.