Crystal golems found throughout the Crystal Labyrinth look like 10-foot-tall githyanki warriors. Like other golems, they are nearly impervious to spells and ordinary weapons.
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Hairless androgynous humanoid construct that can turn invisible
The Crystal Golem appears as a hairless androgynous humanoid, but is rarely seen as it can cast an **invisibility** spell upon itself as a full-round action. It is typically used by wizards and liches who require very discreet workers or guards, and are often programmed to do their work in complete silence. A crystal golem takes full damage from blunt weapons, but only half damage from cutting or piercing ones.
Basic Fantasy Field Guide Omnibus