Kurmokk, the red gorilla, is also tamable. Unlike Scale Belly, he does not have a unique model. He is the lowest level tamable gorilla of this color though, and the only red one in Stranglethorn.
If you look closely at Lord Sakrasis, you will notice that he's wearing a Purple Trophy Tabard of the Illidari (well, the top half of one at least). He spawns across the rope bridge in front of the holy spring on the Naga Island.