April 3, 2006 - The Station Agent star Peter Dinklage has signed on to play the evil Simon Barsinister in the big screen version of the classic cartoon, Underdog.
Frederik Du Chau will be directing the Underdog movie which is scheduled to begin filming this month in Rhode Island. Walt Disney Pictures and Spyglass Entertainment are aiming for an August 2007 release date for the live-action comedy adventure.

The film will be based on the 1960s cartoon which featured a dog named Shoeshine Boy who could transform into the superheroic canine, Underdog.

No other cast members have been announced and there's no word on whether the film will retain the cartoon's theme song (but I'm crossing my fingers).

Source: The Hollywood Reporter