Cyrus Gold was once a normal Gotham Citizen. After being poisoned by Poison Ivy, he was hospitalized. The doctors said that there was no chance of survival. After somehow surviving, he became convinced that he was immortal.
After being poisoned, Grundy's skin became sickly, his hair became grayish-black, and his eyes turned yellow.
Grundy is extremely reckless due to his belief in his immortality.
Grundy is a completely normal human male.
Weapons and Paraphinalia
Grundy doesn't carry any weapons, but he sometimes uses a lead pipe.