This is just an opinion, and it might seem a bit mean... But, if it's tongue is flicking and it's active, take it to the vet and see what they can do for it. They may not treat it if it's illegal to keep them in your area.

If it's not active and flicking it's tongue, it's sad, but it'll probably die anyway and you should end it's suffering.
With how bad the injuries seem, he/she is probably in an extremely great deal of pain.