If you thought McLovin from Superbad was a badass, wait til you get a load of MacReady, Kurt Russells alien-slaying character in John Carpenters classic horror film The Thing (1982).
Based on John W. Campbell Jr.s 1938 novella Who Goes There?, the flick centers on an army base in Antarctica. In this cinematically surreal world, the kindly military personnel take in an abandoned husky dog, which turns out to be a shape-shifting, rapidly multiplying alien life form. The creature begins to kill and replace the men in the base until no one knows human from alien. Oh, the insanity.