What Should Teenage Turtles and/or Rats Look Like?

[Revan]

I often come across posts of users commenting on different versions of the turtles “not appearing to be 15.” I can only assume they are basing this on what 15 year old human teenagers look like, which seems like a stretch to me considering the turtles are obviously not human. So my first question is:

What should a 15 year old mutant turtle look like? Well, there is no scientific answer. Thank you Neutrino, captain obvious. It’s all a matter of opinion.

However, while trying to understand someone’s opinion that “this” version doesn’t look young enough or “that” version looks too young, I thought of Splinter. Now I pose a question to those of you who don’t feel a particular depiction of the turtles looks “teenage” enough:

What are your thoughts on Splinter’s appearance?

The average lifespan of a rat is 2-3 years. So he is most likely around that age when exposed to the transmat waste at the same time the turtles were. We know from just about every incarnation of the turtles that they were indeed “baby” turtles at the time of their exposure. Therefore, Splinter should be about 2 years old and the turtles should be less than a year (approximately). Yet, Splinter is almost always depicted as much older in appearance and no one ever seems to question the way he looks. We are lead to believe he is old and wise but he cannot be much older than the turtles by more than a few years.