[Game] Battlecast Cho'Gath Texture Bug

This is a bug that I just noticed, and I've seen it as long as I have been playing league, but I just realized that its most likely a texture bug. During Cho'gath's laugh before you get 6 feast stacks, there is a black rectangle that is attached from the bottom of his jaw to the top, in the middle of his mouth, like part of his texture is being stretched. Is this part of the model, or is it a bug? Its on his original model too, not just the chromas.

You can't see the bug from the side, so i'm sure its a texture problem: https://imgur.com/a/CMy82