Batman's number one villian deserves his own figure, and since DCD or DCUC has not given him his props, I will.
Gravedigger was an neat character that I wanted to see in plastic, his visuals struck a chord with me so here is my take on him.

Top Hat-DCUC Penguin
Head-DCUC Atom Al Pratt
Torso/Upper arms/Upper Legs-DCUC Cap Boomerang
Lower arms-DCUC Penguin
Lower Legs and coat-Legacy Joker
Glasses-DCD Hugo Strange Secretfiles Batman wave III
Cane-fodder bin

Bored out some of the Penguin's top hat to fit the new head. Trimmed/shaved down the Al Pratt head. Swapped the lower arms with Penguins (they are already black). The lower legs were not a perfect match so some fine trimming allowed them to be streamlined more. They have retained all articulation.
Cropped the round glasses to a rectangle shape.
Painted purple coat black and painted the chest and top hat band a mixture of black and dark blue for some contrast.
Added 2 staps to the top hat like in the comic book.
I think it looks cool.
I hope you like.