A Torothan goat
Torothan goats were a type of animal native to the Torothan homeworld. These mammals had mottled brown hair and four pink horns (two straight, two curved) on their foreheads. Four of these animals were being walked on leads shortly after Jonathan Archer and Charles Tucker III arrived on the planet. (ENT: "Desert Crossing")
In the final draft script of "Desert Crossing", the four alien goats were described as being shown in a pen, though this isn't true of how they are portrayed in the episode.