Mithral golem (HotU)

A mithral golem is capable of quick and lethal action, making it one of the most powerful of golems.

Special abilities
This mithral golem has 25/+6 damage reduction as well as the usual construct immunities to critical hits, death magic, disease, level drain, ability drain, mind-affecting spells, paralysis, poison, and sneak attacks. It also has a spell resistance of 32.