This is Galthrak the Unhinged. I got this pet from a Menagerist Goblin in between Season 11 and Season 12.
The flavor text on Galthrak the Unhinged says: From the time he was a broodling, all he wanted was to be a Rift Guardian. He studied for many years, but was ultimately found wanting. Take him on a rift with you, and he’ll be happy.Continue Reading “Galthrak The Unhinged”