When you think about teenaged mutant turtles with martial arts skills, the first thing that comes to mind is 'Jackass' and when you think about wise, ninja-training mutant rats, the first thing you think about is 'Monk.' Therefore, it's totally and entirely acceptable that Johnny Knoxville has been cast as the voice of Leonardo and Tony Shalhoub as Master Splinter in the upcoming 'Teenage Mutant Ninja Turtles.'

This news (which broke via Deadline), may prove troubling for some fans for a few reasons. First, Knoxville is a truly left field choice for Leonardo, the stoic and commanding leader of the turtles. Shalhoub is odd casting, but it makes a certain amount of sense, but Knoxville suggests that this is going to be a very different take on the characters than fans are used to. You don't cast the star of 'Jackass Presents: Bad Grandpa' if you want a serious performance full of gravitas.

Second, these two are being added to the cast awfully late in the game. The on-set motion capture performances for Leonardo and Master Splinter were completed by Pete Ploszek and Danny Woodburn, but their contracts apparently didn't guarantee them the right to voice their characters in the finished film. Imagine the hard feelings that would ensue if Leonardo ends up being the only turtle to get a new voice...

Anyway, one of two things happened here. Either Paramount always planned on casting bigger names as the voices of these iconic characters or they were disappointed with the voice tracks by the on-set actors and had to make this decision in post-production. With the film currently going back for massive reshoots, the latter sounds very plausible. That may sound bad, TMNT fans, but don't let it bring you down -- if they are recasting and reshooting this late in the game, it's because they are working overtime to fix whatever problems they currently have.

'Teenage Mutant Ninja Turtles' opens on August 8, 2014.

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