Conversation so far:
who plays the monster in pan's labyrinth
As the Pale Man, Doug Jones plays a grotesque monster with an appetite for children.
why did Doug Jones take the part of the Pale Man in Pan's Labyrinth
The director sent Doug Jones an email saying, You must be in this film. No one else can play this part but you.“
did Doug Jones want to be in Pan's Labyrinth
Doug Jones responded enthusiastically to an English translation of the script, but then found out the film was in Spanish, which he did not speak.
did Doug Jones learn Spanish for his role in Pan's Labyrinth
Guillermo del Toro suggested learning the script phonetically, but Doug Jones rejected this, preferring to learn the words himself.

Question: why didn't the director dub over him
Self-contained rewrite: why didn't the director of Pan's Labyrinth dub over Doug Jones's lines