Zach Galifianakis
As it turns out, yes, Zach Galifianakis has always looked like that. The actor had a small part in Below (2002), a submarine horror film written by Darren Aronofsky. Galifianakis played "Weird" Wally, one of the remaining survivors on a haunted submarine. The film received mixed reviews.
Viggo Mortensen
Over a decade before the first installment of The Lord of the Rings ever hit theaters, Viggo Mortensen played Edward "Tex" Sawyer, the central antagonist of Leatherface: The Texas Chainsaw Massacre III. The film was considered a critical failure, but entertained audiences nonetheless. Mortensen made a number of appearances in supporting roles throughout the 1990s until a breakthrough in 1999, when Peter Jackson cast the actor as Aragorn in The Lord of the Rings film trilogy.