From Nookipedia, the Animal Crossing wiki
Tapirs are a species of mammal which resemble pigs and elephants, but are actually an odd-toed ungulate, being closer relatives to horses and rhinoceroses. In Japan, tapirs are called baku and are named after their resemblance to a supernatural creature (yōkai) that feeds on dreams through its elongated snout. In the Animal Crossing series, they are introduced in Animal Crossing: New Leaf. There is currently only one tapir: Luna, who allows the player to share and visit dreams in New Leaf and New Horizons as a reference to the mythical baku.