Red devil

[deleted]

**This might be considered a Spoiler, be warned.**

I think the only explanation is that it was "siete", the ranch hand.

The toolbox the devil was holding kind of suggests this, and you also see that the rest of the family was asleep, except for the boy that was witnessing him roaming the house.

The director himself can answer it for you.

This youtube channel has another little videos that give some hint about why the director did this movie this way.

I recommend that you only see the videos after you have watched the movie.

http://www.youtube.com/watch?feature=player_embedded&v=tFqWAkaa8PQ

Judging by how terribly the cgi was, with the tail on wrong side, I interpret is as reflection on the film-making process, and a breaking of the fourth...uh, I'm going to stop wasting time now