Mike Mignola, the illustrator and writer most famous for creating Hellboy, did a one-off comic book in 2002 called The Amazing Screw-On Head.
The titular character works as a secret agent for President Abraham Lincoln. Screw-On Head, an expert in the occult, is literally what his name implies, a mechanical wonder who attaches himself to various mechanical bodies equipped to carry out his duties.
In 2006 the Sci-Fi channel (now SyFy, boo) commissioned an animated pilot of The Amazing Screw-On Head and Mignola delivered.
Alas, it was not picked up as a series despite boasting the voices of Paul Giamatti in the lead role, Patton Oswalt as Mr. Groin, David Hyde Pierce as the villain Emperor Zombie and Molly Shannon as Patience, Screw-On's ex, now a vampire aligned with Zombie.
The show, like the comic, is wickedly creative and very funny -- a steampunk melodrama well aware of its own ridiculousness. Here's the trailer:
You like? Watch the whole thing here. It's only 22 minutes long.