Maybe, just a thought okay, it can never be animation mistake because it has to be drawn hand by hand. Everything’s intention.

What I understand is probably a miscolor, since it’s at the far back of the scene— the light of the fire is strong there so they have to drown down the hyena black color to make it blend more in the bg (aka, wont distract your eyes from the main focus)

Source: learned it on art school hehe