What animals are born full grown?

Answer 1

Taking "full grown" as being able to exist immediately outside the mother, many herbivorous animals can function as the adults do, but will still need the mother to nurse from. Reptiles and fish that hatch are usually smaller versions of the adults, and have to feed on smaller prey than the adults.

The term precocial species pplies to those in which the young are relatively mature and mobile from the moment of birth or hatching.

Equine (horse) and bovine (cow) babies can not function without their parents as they do not have teeth and would starve to death. But creatures such as turtles, crocodiles and octopuses are born/hatched in a developed state and can survive without their parents' help. Some, like crocodiles, do get protection for a short period until they mature.

As a general rule, mammals need parental assistance in the beginning of life.

Answer 2

Some animals that are born fully developed or nearly fully developed include marsupials like kangaroos and koalas, where the young are born in a very immature state and then crawl into the mother's pouch to continue growing. Insects such as praying mantises also go through incomplete metamorphosis, where the nymphs resemble miniaturized versions of the adults.