Unfortunately, I seem to be having some trouble with that center part. It appears randomly, and is only somewhat visible when the character is running right instead of left. It's bizarre. I'm sure I'll have it worked out soon but I'm using this blog post to vent and also to brag about Murilo's art as if I had anything to do with it.
Also, not to worry, that jump animation is not permanent! Just for playing with the coding side of things
Hopefully by the time you finish reading this, the gif will be finished loading.