That was over 14 years ago in 2007.
Today he is 43, and has starred in 66 movies in total, 58 since Superbad was released.
In Superbad, I think Bill Hader looks:
Superbad scores 7 out of 10 on The Movie Database.
Bill Hader's first acting role was as 'Eric' in The Pity Card, released in 2006 when he was 28.