Put the summary of the bug you're having here
What I expected to happen was that the horse wouldn't move at all but his head and body did.
*What actually happened was that the horse's body and head moved when I moved my mouse when I had the GUI open. When I move my mouse vertically, the horse's head looks like it's shaking it's head. When I move the mouse horizontally, it moves the horse's body back and forth.
Steps to Reproduce:
1. Tame a horse and open it's GUI.
2. Move your mouse vertically and horizontally to see if the horse's head and/or body moves.