Yea, I was thinking dekayi, too...

Anyhow...it doesn't look great, but it doesn't look fatal, either. It looks like there might be a cut on the back of the jaw. Is that true? If so, I would recommend getting him isolated and off of any substrate. You could use plain white paper towels, and it would help him heal cleaner.

It does look broken...this may require a vet to realign the lower jaw bone. You could try, but I don't recommend it unless you are familiar with recognizing the difference between a clean break and a jagged break by touch. If it's clean, it should go right in place. If it's jagged...it will take a qualified herp vet with a steady hand to get back in place. Either way...unless you're experienced it is best to go see a vet.

Until you can get to a vet, treat that cut, if it is a cut, and get him on clean, white papertowels with heat and hides. IF you can find some slugs, you could offer them to him. But a vet trip is definitely in this little guy's future...