Donkeys belong to the class Mammalia. More specifically, they belong to the order Perissodactyla. Within that order, they belong to the family Equidae.
Mammals
The donkey is a vertebrate
Penguins belong to a vertebrate group called aves.
The vertebrate group in which humans belong to is the mammal group.Humans belong to the Mammal group.
The apes
reptiles
reptiles
reptile
fish
They are amphibians
bird
Sharks belong to the vertebrate group known as Fish. Specifically, they belong to the vertebrate group known as Chondrichthyes - all sharks and rays - which have skeletons of cartilage rather than bone.