This a “miniature” pig, but it’s a baby. Miniature is relative because they get way bigger than that, like much heavier than a large dog, but smaller than a regular pig.

They go by many different names but there are slightly smaller breeds.

It's for sure a pig though, just a little smaller and they can get up to 200 lbs which is still a monster pig. I've heard of people deliberately misleading people by selling "tea cup" pigs that are just under fed pot belly pigs that end up getting giant.