It’s an undead baby dragon, produced by a failed magical spell. It probably would be cute if it weren’t partially decayed.

Young dragons are relatively defenseless. They are born with relatively soft scales, which are shed and replaced with harder ones as the hatchling matures. Once a hatchling’s wings grow in, it typically marks the beginning of maturation. At this point they are often capable of hunting on their own and are usually left alone by their mother.

Urggghh was killed by a fiendishly difficult spell gone wrong. Due to his highly magical nature and the bits of mana buried underground, it's believed the residual magic in his body brought him to "life". He recalls that mana was important to him before but does not seem to know its purpose, and even if he did, he likely couldn't make use of it. Urggghh is hardly a threat to anyone nowadays: if he's given a mana crystal, he happily gnaws on it and ignores everyone else.