Swampy is one of my two favorite DC characters; I started reading his book with #4 of the original series. While I thought Moore's take was amazing, I don't think it would work well in a movie. There's way too much background and explanation needed to make the Moore approach work in a single movie. In short, the character would be far more relatable if he was Alec Holland, rather than a plant elemental who thought he was Alec Holland, and that's what you would need for the film to appeal to the audience. An approach like that taken in the TV series, where he was definitely Holland with a lot of the attributes of the Moore version, would be the best take for a good movie, I think. As for cast, I imagine they'd go CGI for Swampy himself, so I don't imagine **** Durock would be reprising the role physically (although I think a good case could be made for him in a well done costume like the TV show had; Hellboy was a lot better with Perlman actually made up than if he'd been CGI). Wouldn't mind him doing the voice, though.