I have bottle raised kittens, and hand raised several birds. I once nursed a painted turtle back to health after it was attacked by a raccoon, and had 3 of its legs bitten off. I kept it as a pet for several years, then donated it to a pet shop to use for breeding stock.
I've had mice, garter snakes, frogs and toads as pets. (I used to teach biology, okay??) The tree frogs were the most interesting... they could cling to glass, and walk up walls! Most exotic pet I've had was an American chameleon (anole). I also have raised a lot of insects, as I used to teach entomology and pond study. When I taught outdoor ed, some of my students learned how to identify the eggs of the monarch butterfly, and we got to watch the entire life cycle, from egg to butterfly.
Worst experience: my mom stepping on a fully grown monarch caterpillar, as she went to open my bedroom window one morning. I can still hear her scream in my memory....
She also wasn't too happy with the dragonflies that hatched out of my aquarium in the middle of April, and went zooming around the basement!