Solomon Grundy

Another version of Grundy appears in the Batman episode "Grundy's Night". In this version, Grundy was created by the working class citizens of Gotham to wreck havoc on the rich landowners who polluted the land. According to legend, Grundy rises from the dead on Halloween night to kill the descendants of the landowners. In the end of the episode, Grundy is revealed to be Clayface, although something is shown rising from the swamp whilst a moan is heard.

Bio
The legendary swamp zombie who terrorized founders of Gotham one hundred and fifty years ago and promised to return one day to do the same to their descendents.

Bio: Solomon Grundy, a creature made out of the rage of villagers whose land was turned into a swampland for the industrial waste that was cropping up from the rapid expansion in Gotham’s early life, rose from the mud to take the things most precious from those that signed the papers that started the waste dumping process. It was said that a hundred years after he first rose, he would rise during a solar eclipse and take the riches of the families’ descendents that he stole from a century ago.

Fortunately for Gotham’s wealthy, the Solomon Grundy that showed up on Halloween night was really Clayface in disguise. After a tussle with The Batman, Clayface was encased in wax and taken back to Arkham.

Two kids hanging around the Gotham Swamp on Halloween Eve claim to have seen Grundy rise from the swamp after Clayface had been captured.

Powers
Solomon Grundy is arguable one of the strongest villains in the DC Universe, if not one of the heaviest hitters regardless of evil or good intentions. He is also incredibly invulnerable, able to take massive amounts of damage with little injury. When injuries do occur, his body rapidly in a matter of seconds heals up the wounds, sometimes enabling himself to re-attach severed limbs right after they are hacked off. He can also continue fighting for days straight, making him incredible resilient in addition to his huge strength.

Because he is artificially animated, Solomon Grundy isn't affected by disease and ailments like standard humans. He doesn't need to eat, breath, sleep or drink, although occasionally he has fallen asleep in the sewers and attempted to feed on intruding humans to the swamps he calls home. Most likely this is a side effect of his re-animation that, over time and when near to transforming into Cyrus Gold, his body, in preparation, begins to systematically shut down in preparedness for the transformation, rendering him lethargic. The hunger is similar to movie zombies, but isn't as intense, suggesting that to fuel his body he needs to intake living flesh to sustain his own semblance of life. But unlike Romero zombies, he isn't biased and will eat anything from rodents to even attempting to eat Killer Croc during a territorial squabble.

Solomon Grundy, despite being undead, can and has died multitudes of times. However, with each death, he re-animates soon after, acquiring even more strength than before and sometimes a personality with average to high intelligence (although this is incredibly rare). Grundy for a time was able to control plant and wood energy due to the amounts of tree product that had formed inside his decayed body. This proved useful in defeating Alan Scott the Green Lantern several times before eventually losing this ability.

In the recent Brightest Day/Blackest Night cross-over event, Grundy was given a Black Lantern ring. Alongside his super strength and invulnerability, he was given access to the ring's dark capabilities.