I think this is a reference to Urashima Tarou (or just the fact turtles live long).
>>283290414
This collection doesn't reach that far. Supposedly it's a summary log of some of their xitter posts but I can't find their account after mildly thorough investigation, which leads me to believe it was either nuked or it's a private account and they only share art publicly through pixiv dumps, but they haven't updated since last year. Hopefully didn't spaz out and quit art which is a common occurrence among online artists.