Pig
Pigs are animals in the Real World. They also appear in the Mario series, in multiple games. They first appeared in Super Mario Land 2: Six Golden Coins as bosses known as The Three Little Pigheads, who were three Pigs that parodied the story of The Three Little Pigs. (Super Mario Land 2 also featured a Pig sub-species known as the Cannon Pig.) They next appeared in Paper Mario, under the name of Li'l Oinks; these Pigs are used to get certain items. Appearing again, a strange, hog-like creature named Hoggus appears in Wario Land 4; Hoggus could even make Pigs appear by sketching them on his pad. Pigs then appeared in Paper Mario: The Thousand-Year Door, which had Doopliss turning the citizens of Twilight Town into Pigs with the ring of a bell. Doopliss was defeated, and everybody was eventually turned back. Mr. Hoggle, an anthropomorphic Pig, also ironically ran a Hot Dog stand in Glitzville. In Super Paper Mario, there are several foes that resemble Pigs (such as Squiglet and Pigarithm).
In Donkey Kong Land, winged Pigs known as Hogwash appear; additionally, humanoid, possibly part-mechanical Pigs known as Hogs appear in Donkey Kong Jungle Beat.