He-Man and the Masters of the Universe - Season 2 Episode 4 : Rise of the Snake Men (1) 2004

Desperate times call for desperate measures; in an effort to prevent the return of the Snake Men, the Masters of the Universe seek a temporarily alliance with the Evil Warrirors. Skeletor agrees to join his forces with theirs, but then ambushes the Masters when they arrive. With the Masters and the Evil Warriors preoccupied by their own battle, Kobra Khan and Rattlor are able to make their way to the Void within Snake Mountain, freeing their ancestral allies: Tung Lashor, Sssqueeze, Snake Face, and the leader of the Snake Men, King Hssss!