There are many jokes about about I.R. and the Red Guy not wearing pants, but never about I.M. or any other animals not wearing pants. In the case of I.M. he is fully covered by fur and doesn't have a big butt, just like most other animals. There are also animals who don't have any visible embarrassing parts and those who do are very minor characters, thus not used for many jokes.
When Weasel and Baboon were searching for the legendary Big Butt (The red guy, of course). Baboon felt sorry for a snowman and decided to give it his clothes. This seems funny until you realize, that the final stage of hypothermia is getting the idea to take off your clothes. Baboon was dying, and Weasel just shrugged it off!
The supporting casts of Yogi Bear and The Flintstones can be seen at the different retirement homes in "I Am My Lifetime", but Yogi and Fred themselves are nowhere to be seen. Did they both meet early demises from a lifetime of bad eating habits?
Them having bad eating habits it's not the only possible cause of someone dying. But considering they weren't shown there, it is very likely that they died, regardless of the cause.
