Stone harpies

These are enchanted statues, looking like Harpies. They are used a magical guards to important places, and have no own will and mind. However, they are extremely dangerous in combat, and only the most experienced adventurers should dare to attack them.

Stone Harpies are usually used to guard important places like treasure chambers.

Lore
''Harpy is a misnomer, for the name actually refers to any enchanted statue capable of human-like animation. In general, these stone constructions are used to guard valuables long-since secreted away in dark tombs.''

- from "Beyond the Serpent Pillars", Ultima VII/2

Notable examples

 * Actually not an example from the Serpent Isle, the Sultan of Spektran has one to guard his treasure chamber. Since Stone Harpies are unknown to Britannia, it can be speculated that he has got it somehow from Serpent Isle.