The Season 3 finale of Gotham was jam-packed with surprises, not the least of which was the revelation that the real name of longtime henchman Butch Gilzean is Cyrus Gold, better known to DC Comics fans as the original identity of Solomon Grundy.

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Over the first three seasons of the Fox drama, Butch (played by Drew Powell) served as an enforcer for Fish Mooney, Oswald Cobblepot, Tabitha Galavan and, finally, Barbara Kean, who shot him in the head after learning of his plot to betray her.

The producers of Gotham haven't been coy about their plans for the now-vegetative character, who will be dumped into Slaughter Swamp by hospital administrators more concerned with their bottom line than with his care. When Butch (or Cyrus, if you prefer) emerges from the murky waters, he'll be reborn as the hulking undead monster Solomon Grundy. However, it's not only his physical appearance that will change.

"There have been various iterations of Grundy throughout the years," Gotham executive producer John Stephens told CBR. "He has the same mental capabilities as the most well-known version of Grundy. The way certain things will change is there are moments when elements of Butch’s personality and memories will come back into the fore of Grundy."

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"One of the themes for the show has always been the idea of the fluidity of identity, and the creation of identity," he continued. "So, even when he gets reborn as Grundy, we’re asking the question of, 'Is this Butch’s new personality?' Or, 'How does he create a third personality that is part Grundy and part Butch?'”

Introduced in 1944 in All-American Comics #61 as an enemy of the Golden Age Green Lantern, Solomon Grundy was a murder victim whose body was dumped into Slaughter Swamp, only to be reanimated 50 years with the only knowledge of his previous existence being that he was "born on a Monday," a line from the 19th-century nursery rhyme that gave him his name.

A revenant with superhuman strength and stamina, over the years Grundy has been a fixture of comics, video games and television, appearing perhaps most famously as a member of the Legion of Doom on the animated Challenge of the Super Friends.

Returning Thursday at 8 p.m. ET/PT on Fox, Gotham stars Ben McKenzie as James Gordon, Donal Logue as Harvey Bullock, David Mazouz as Bruce Wayne, Robin Lord Taylor as Penguin, Cameron Bicondova as Selina Kyle, Erin Richards as Barbara Kean and Sean Pertwee as Alfred Pennyworth.