Question

which animals do not have leg

Answer 1

snake, whale animals don't have leg...

Answer 2

The reptiles are the animals that do not have a leg

Explanation:  

Evolution has given each organism its present day structure and parts. According to evolution whichever part is required by the organism for survival has grown whereas whichever organelle is not required has lost its occurrence. Accordingly, the animals used to mostly crawl or swim in water and land, these limbs were lost. This loss has occurred slowly for about 3.6 billion years.