The largest animal on Earth, the blue whale, would also be the hardest to take care of. It would be so difficult that no one has even attempted it, although there are some smaller species of whales that can be kept in an aquarium.
the cacahuhu
Human is the most demanding and least mature to care for all in all
Chihuahua
take care of them
Tooth, or, specifically, tooth enamel is the hardest animal tissue.
I'll go on a lim & say poison dart frog. Why? Do you have a death wish?
Humans are neglective.
horse
Crustaceans.
an animal specialist is basicly an ANIMAL doctor. and they help take and care of animals, like vets
birds duck
Foopets.com
Animal Doctor does