Bill Hader is very prominent in American comedy from television to film. Most notably, he regularly stars on Saturday Night Live. One of his more popular characters on Saturday Night Live is Stefon, Weekend Update’s flamboyant Correspondent.

Often, writer John Mulaney will change the jokes in a sketch right before the sketch airs. Many of the new lines catch Hader off guard, making him break character and laugh. Mulaney also often changes the cue cards so that Hader will read something he didn’t expect to read and get a genuine laugh.

Hader is most famous for his roles in Superbad, Hot Rod, and Tropic Thunder. He has also been on the production team of South Park. Check out a clip of Hader breaking character below