List of my RotTMNT Headcanons
-Yokai age slower than humans, so while Draxum is middle aged in Yokai terms, he is numerically hundreds of years old. He lived through the Yokai banishment and that fueled his motivation of his villain story in Season 1. Since his “childhood” at least partially took place on the surface, old buried nostalgia fueled his redemption arc in Season 2.
-Baby Leo took his first steps running, literally.
-Raph hates medical talk, he's very uncomfortable around blood and he's a sympathy crier.
-Don has chronic pain in his back specifically from his battle shells. His first prototype was fairly heavy, especially as he added features, and over time he was able to lighten it to be comfortable while worn. However, every once in a while he'll have chronic pain days that are not impossible to power through but still very annoying to him.
-Mikey hides snacks in Don's lab so he doesn't accidentally starve to death while working in the Zone. There are supportive sticky notes and doodles attached to them.
-Sick days: Raph gets clumsy and cranky. Donnie pretends he's not sick even when he is actively blacking out. Leo gets clingy and hug-y. Mikey gets quiet and sleeps a lot which freaks the rest of them out.
-In their tot days, baby Mikey would often call his brothers "Lee", "Dee-Dee", and "Raphie" to the point that the other brothers picked up the nicknames as well. As they got older those nicknames were decided "too childish", but sometimes those old nicknames reappear.
-Donnie loves closed spaces and is mildly agoraphobic. This is why his bed is Like That.
-Donnie is older than Leo. You can’t change my mind. Leo's "big brother characteristics" stim from being a big brother to Mikey, not Donnie. However, Don does not necessarily like being the second oldest, as he is inherently seen as a backup authority in family situations. So, he tries his best to pawn those situations off on Leo.
-Leo likes Sonic the Hedgehog. His favorite game is Sonic Heroes, and he was into the Archie comics. He tried very hard to get the rest of the family into it, but they couldn't love the series like he did. However, years later Donnie was subconsciously inspired by Robotnik to create Shelldon's AI.
-April is an only child in her human family. Her parent(s) value hard, honest work, which is why April is always focused on having a job. This is also why she always seems to be the only one home most of the time.
-April has told her parent(s) about her “friends from school”. They aren't fools though, they figured it out a long time ago. They trust their daughter’s judgement and recognize that “the mutants” are just kids, and are waiting patiently to officially meet the Hamatos. They don’t know about Splinter being a rat, though.