He would have been better as Fletch than Underdog, but what can we do?!?

‘Earl’ Star Gives Voice to ‘Underdog’
There’s no need to fear — Jason Lee is here
Jason Lee is set to voice the titular super-pup in the upcoming big screen incarnation of “Underdog.”
Set up at Spyglass Entertainment and Disney, the “Underdog” pic will be mostly live-action, though the main character will be animated with the “My Name Is Earl” star lending his pipes.
Premiering on NBC in 1964, “Underdog” told the story of a canine-superhero with an occasionally annoying tendency to speak in rhyme. By day, he was just Shoeshine Boy, but he could become Underdog whenever Polly Purebred was in danger.
The character was originally voiced by Wally Cox.
The only other actor already cast in Fredrick Du Chau’s film is Peter Dinklage (“The Station Agent”), who will play the evil Simon Bar Sinister.
Lee is no stranger to vocal work, having played Syndrome in the Pixar smash “The Incredibles.” This summer he appears in motion-capture form in “Monster House” and drops by pal Kevin Smith’s “Clerks II.”
According to The Hollywood Reporter, Lee will also use part of his “Earl” hiatus to direct a short film starring Giovanni Ribisi and Beth Riesgraf.