Sparamantur
From Tomb of the Serpent Kings
Sparamantur was a skeletal snakeman. He laid in a crypt accessed via the atrium on the second floor. The passage of time buried the crypt and Sparamantur under a mountain of rubble, until enterprising adventurers dug their way into the chamber. They defeated him by dropping the door onto him from above, crushing him beneath it.
He carried a magic greataxe.