
a young dog = puppy

a young cat = kitten

a young bear, lion, tiger, or wolf = cub
a young bird = chick

a young duck = duckling

Learn more: English Vocabulary Words for Birds
a young pig = piglet
a young horse = foal

a young deer = fawn

a young sheep = lamb

a young goat = kid

a young frog = tadpole

a young butterfly = caterpillar
