Hista is an giant python seen in the "Legend of Tarzan". Hista makes a cameo apperance in Animated vs. Video Game Villains War and in Disney Heroes Vs Villains War.
Animated Vs Video Game Villains War
A Wizard's Transformation
In this war, Hista is the snake transformation of Blackwolf, along with the other snake form, Heavy Anaconda. In fact, Blackwolf's transformation was a mix between these two snakes. Hista was only shown when he takes down Bowser's gadgets and when Bowser throws to the snake's tail a giant rock, heavily damaging him.
Disney Heroes Vs Villains War
During the fight between Kaa and Tarzan, there are brief clips of Hista. Whether Hista scenes are only part of Kaa's body or it is really Hista, helping Kaa to defeat Tarzan is unknown.