Goats were variety of hoofed mammalian quadrupeds native to several planets including Earth.
Q once turned Jean-Luc Picard into a goat, just prior to abducting him from the USS Enterprise. (TNG comic: "The Gift")
The Denebian horned goat was a notable angry looking species. (DS9 novel: Devil in the Sky)
An Angiran gaya is similar to a goat, but larger and with longer hair. (TOS novel: Shadow Lord)
When Nog tried Andorian citrus drink he thought it smelt like goat and lemon oil. (DS9 novel: Avatar, Book Two)