[That, then, presents a much more difficult question for him, and the way that he falters is apparent. It's hard to say why, precisely; maybe it's the way it's framed, the way it can't be answered without combining Rohan and the snake together into one single entity. His body shouldn't have done anything to adapt, maybe, because these changes are supposed to be something that happens to people, not a symbiosis. It's harder to separate and other the monster with a question like that, and it sets him off-balance.

But he's determined to answer it. He focuses instead on the phantom sensation of where Rohan's comparatively cool hands had rested against his wing and back, and makes himself think, trying desperately to reframe his perspective at least enough to answer it adequately.]

You got your fangs. You can spit poison. You're...always cold.

[You seek warmth, he almost says, but doesn't when it makes him abruptly aware of just how close they're standing.]

The way you digest things changed. You had to...be able to slither, instead of walking. You're not using your hips to control movement anymore, it's...lower in the tail itself? When bipedal creatures walk, a step is really just falling forward and catching themselves. You don't move like that. You...wind. And you cling. When I pick you up your whole body works to stabilize yourself.

[...]

Your tail is attracted to me.

[HE MEANS TO HIS BODY HEAT BUT THANKS FOR THAT ANYWAY JOTARO GOOD HUSTLE.]