Robert Downey Jr. for 'Perry Mason' role?

Robert Downey Jr., who has played a superhero in "Iron Man" and a 19th century sleuth in "Sherlock Holmes," may add another unlikely role to his resumé: Perry Mason, the iconic fictional defense attorney.

Little is known about Downey's potential Perry Mason movie (and potential franchise), though Variety reports that Warner Bros., the studio behind "Sherlock Holmes," is involved. The movie may be set in 1930s Los Angeles, which would suggest a noir; the novelist who created Perry, Erle Stanley Gardner, is said to have inspired Raymond Chandler's early work.

The role may seem like an odd fit for Downey. Raymond Burr's portrayal (in the 1957-1966 television series "Perry Mason") remains definitive: broad-shouldered, intensely serious, a veritable pillar of justice. In other words, nothing like the lithe, rakish Downey, who always seems to have a glint in his eye and something up his sleeve.

That, however, is Downey's secret weapon. He was fine as a cynical journalist in "The Soloist" and passable as a beleaguered yuppie in "Due Date," but Downey is best when he's miscast. His Iron Man upended the sincere superhero stereotype, coming off as refreshingly funny, sexy and hip. In "Sherlock Holmes," Downey slyly undermined the famous detective's inherent pomposity and played him as a squirrelly, unreliable eccentric.

A decade ago, Downey was struggling with drug addiction and losing work because of his arrests. If the Perry Mason project takes off, it could give Downey his third concurrent franchise -- surely a record of some sort -- and provide him with yet another unlikely role: the hardest-working man in show biz.