According to relevant sections in the film's official novelisation the creature is described as being a "demon". Beyond that, there's really no further useful info.
Then, as if the worst were surely done, something dark and wet poked its snout from Damodar’s nose. Something pale as death slid from his ears. Damodar shrieked in terror as the mindless, ropy things snaked out of his head, hissed, coiled in anger, then struck at one another, struck at his mouth, struck at his eyes…
“I am sending a companion along to remind you not to fail me again,” Profion said. “A gentle reminder not to make anymore mistakes, my friend. I suggest you take a lesson from your foes and follow the Empress’ tracker. She appears to be somewhat more proficient in her work than you. She will lead you to our missing friends and the scroll. And this time, Damodar, do not fail me.”
Profion paused, watching as Damodar writhed in hellish pain. He found great pleasure in the sight, for he saw a fine irony in what this man had become. Damodar, who masked his evil with the handsome features of a fine aristocrat, now faced the world as the monster he truly was.
“The beast is in us all,” Profion whispered, “and it takes little magic to bring the creature out.”
At once, Damodar’s flesh began to writhe, tremble, and stretch in
tortured disarray. Sharp tendrils of hellish blue lightning began to
whip his body. A terrible cry escaped his lips as the corners of his
mouth began to crawl up his cheek, smother his nose and envelop his
eyes. The damp, quivering tentacles of the demon in his head snaked
out of his ears, his nose, and his mouth, jerking frantically, wildly
about as if they sensed their time had come. Damodar sank to his
knees, clutching the distorted flesh that quivered atop his head and
rolled across his face. The watching mages and soldiers shrank back in
horror, each one aware that Profion’s wrath could just as easily fall