Say your friend invites you to come over and see her new little pup. Who doesn't like puppies, right? So you go racing over there with a giftwrapped chewy bone, and discover . . .
. . . she's got a tiny young shark in her fishtank.
Because the term for a baby shark is a pup. And you had better be prepared so you don't say "Ew," and make your friend feel badly. Though if your friend likes to snuggle up with sharks I suspect she can take it. So consider yourself forewarned and forearmed for any baby walruses, rats (also called pinkies), otters, hedgehogs and moles. Most of those are a stretch, but you never know.
By the way, an echidna's child is a puggle, while an alpaca's is a cria. These and much more young'un nomenclature may be found at the Baby Animal Names page on the adorable ZooBorns site.