Cell walls !
The common protein found in all animals is collagen.
They are all animals
All animals have to go throw pregnancy first which is common in all female animals.
they all have a cell membrane
They all eat have eyes or
Yes, all chordates have a tail sometime during their development, although its not necessarily seen when the animal is adult. In many animals its a vestigial structure
Deserts occur on all seven continents and there are no animals common to all.
2 common animals are the raccoon and the bear
All animals in antarctica have fat deposit under their skin.
Teeth because all animals need to chew their food.
they all have brains
Mitochondria