Ruby golem

Ruby golems are 9 feet tall, with facets ranging from bright red to almost black. They are softer than other gemstone golems, but highly resistant to magic.

Special abilities
A ruby golem has 30/+1 damage reduction, but also has 100% vulnerability to sonic damage. In addition, it has the usual construct immunities to critical hits, death magic, disease, level drain, ability drain, mind-affecting spells, paralysis, poison, and sneak attacks, as well as immunity to spells of level 9 or lower. Furthermore, this golem regenerates 10 hit points per round.