re: well uh
there is quiet obviously the tail, i imagine the yellow on it is sort of like scales, and is probably somewhat brittle, and the horns are supposed to curl more honestly, not like a ram's horns but they curl more than how i drew
there are also the holes on the sides of the body, which are where his hands used to be. these holes tend to ooze a bit of blood every now and then.
there's also his mouth, which is rather jagged, those sharp edges can sort of function like sharp teeth, though really, it's more like the skin fell apart in those areas.
his body might also have various scars and the like.
his wings are like a wyvern's, if that helps you draw them.
his feet are very weak and shaky if he's to walk, and they probably might be like.. i guess rather dirty and roughed up? since he doesn't wear shoes wherever he goes.
his face, mainly areas between or around the eyes, would probably ooze like the holes on the sides of his body.
uhh i dunno if there's much else i need to say-

and as for limitations, you can mostly do whatever you want, i don't want him to be attacking someone/something though since while he is monsterlike, he's rather docile and a scaredy cat
(i already mentioned probs but i do have some tags to use, #eliplslook, #monstersau, and #sketcholooko, so me and my friend who also sorta owns the character can see)