Arimaspi

Arimaspi is a minor villain appearing in My Little Pony: Friendship is Magic. He is a giant monster with horns.

In the episode "The Lost Treasure of Griffonstone", his story is explained by Grampa Gruff, and shown in a flashback: Arimaspi stole the Idol of Boreas, which united the griffons of Griffonstone. King Gudo and his griffons tried to fight him, but he overpowered them and escaped out the window. As he crossed a bridge above the Abysmal Abyss, the bridge was struck by lightning, sending him falling to his death, and taking the idol with him.

Later, as Pinkie Pie and Gilda try to save Rainbow Dash from falling into the Abysmal Abyss when she is injured trying to recover the idol, they reach a lower area where Arimaspi's skull can be seen next to the idol.