I did have a Mumba leashed, it's no where to be found now, but the leash won't let me use it again at all, it says the Mumba is leashed. 

thanks for noting this! It's been a known issue for a bit (the Mumba likely got stuck in a tree or something and the super elastic invisible leash is still tied to it) ill address this on next version so that leashed animals have the same behavior as pulled items!

Fixed for 0.4.3