The Cabin in the Woods Wiki

So it seems we've been adding monsters that are either not in the movie, or are duplicates of monsters we already have.

Freddy Krueger and Pumpkin Head are not in the movie, if they're not seen, they're not in.

Alien Creature and The Alien are not different monsters, but concepts of the Alien Beast.

Dark Spirit is simply the Wraith, yeah, the colors are different, but there's WraithS, so it can simply be another differently colored Wraith.

Big Gorilla Wolf Motherfucker does not appear in the movie.

Cow Skull Giant is simply a behind-the-scenes look at the Bull-Headed Phantom.

Demon is a concept for the Red Dismemberment Goblin.

And for the love of all that is holy, please don't just say x summons y if it hasn't been officially stated as canon.