10 Horror Movie Mistakes Left In To Troll You

Of the many, many ludicrously entertaining moments in The Cabin in the Woods, one of the funniest sees poor control room technician Steve (Bradley Whitford) mauled to death by the elusive Merman he was so desperate to see. Better still, his blood spurts triumphantly out of the creature's blow-hole.

This effect was actually a mistake, though. Originally, the Merman wasn't supposed to spurt any blood at all, but the special effects technicians convinced director Drew Goddard to give it a try.

The effects team ended up dumping their entire surplus supply of fake blood into the giant squib, resulting in a wildly over-the-top, volcanic eruption of gore.

Ultimately the final sequence was cut down from an even more ridiculous and prolonged explosion of blood, but the version we got was nevertheless the result of a happy on-set accident, and one which fit the third act's generally insane tone like a glove. Goddard would've been nuts to cut it.