If Silent film actor Lon Chaney live to see this character, he would think Clayface was based on him. That may be partly true. Clayface I think is one of Batman greatest villains he ever face. Try fighting a guy who’s made out of clay and change his appearance!
Ron Pearlman is NOT the first actor to play Clayface, in fact Clayface first appear in The New Adventures of Batman! Not sure who voice him in that one.
Batman the animated series did introduce him in a big way giving him a two part episodes of how Matt Hagen became Clayface. In the series I think Clayface was such a tragic character from the start, had a horrible car accident and many month or years later he became Clayface and later we see him falling apart! Did I mention he was in love with Summer Gleason til Batman stop him? Check out The Batman Adventures issue #8!
What I like about Clayface in Harley Quinn is they show a lighter side of him, happy, funny and make a great teammate for Harley!
My favorite comic story of Clayface is a two part Wonder Woman story I just read recently where he steal Wonder Woman clayform and making our hero looking like Donna Troy twin sister! That was a good story. The one thing that suprise me was when @Jay_Kay told me I should read Batman Rebirth. So I did, to my suprise Clayface was on a good side! It’s so nice to see one of Batman’s villain turn good.
I could just go on talking about the character, @HubCityQuestion just wrote a great article about the character, what’s your favorite thing about Clayface? 
There are so many.
On screen I have to say it has to be the Clayface fro The Batman. I enjoyed the story.
On the page it it Detective Rebirth. Enjoyed his redemption arc and friendship with Cass.
But they’re all great. I’m just a big Clayface fan.
I loved Shirley Walker’s Clayface theme from Batman: the Animated Series.
Oh, certainly. As one character said in Karlo’s first appearance (Detective Comics #40):
That’s an obvious nod to Chaney’s career. Of course, his name also implies some inspiration from Boris Karloff. (Matt Hagen was the name of the Silver Age Clayface, and while Batman TAS took his name and powers, the show took Clayface’s backstory and characterization from the Golden Age Clayface, who was originally just a Phantom of the Opera-esque villain.)
The thing I like about Clayface is the potential for deception through his shapeshifting abilities. You can get some really paranoid stories out of him as the villain.
Scary Clayfaaace! /acting
Clayface is one villain I’d really love to see done well on the big screen.
