Mammals

They have hair

Mothers feed their young with milk

They breath throught their lungs

Most are born from their mother's womb

They are warm Blooded

Monotremes: mammals that lay eggs

Platypus and echidnas are the only examples

Marsupials: they are born very small

Kangaroos, Koalas and Opossums are the main examples

Mammals without much hair

Dolphins and Whales are the main examples