For an actor who has carved out a niche playing impish sidekicks and clueless buffoons, David Cross is well-aware of his limitations. “I auditioned for The Big Lebowski and I thought I did a really good job,” he tells Vulture. “But then I saw what Philip Seymour Hoffman did with the part, and I was like, ‘ Oh— that’s the way to do it.’” Of course, aspiring sketch comedians have been saying the same about Cross ever since HBO debuted his endlessly influential Mr. Show With Bob and David. In the years since, Cross has appeared in a spectacularly wide range of programs and movies — a fact that will be nicely illustrated this Friday, when IFC airs the season finale of his low-budget pet project, The Increasingly Poor Decisions of Todd Margaret (in which he plays another clueless buffoon), and DreamWorks releases Megamind (in which he voices Will Ferrell’s impish sidekick). Vulture asked Cross to take us on a backstage tour of the highs and lows of his career, from his comic roots in Boston to, yes, that weirdly controversial role in Alvin and the Chipmunks.