Because depicting the Hulk, Rhino, Kingpin, the Blob and Colossus as regulation LEGO minifigs looks silly, LEGO Marvel Super Heroes uses LEGO Big Figures. Hmph.

I suppose it's one way to do it, but they do lose some of that LEGO charm when they go large. Alas, the Hulk Big Figure made his debut last year in the LEGO Marvel Super Heroes Avengers sets, so precedent has been established.