Four paranormal investigators, trying to build a following on YouTube, take a job at a high-school that is purportedly being haunted by the vengeful spirit of a young girl known as Bloody Mary (AKA Cotton Girl), who has been summoned by one of the students.
With gags about H.I.V. and Parkinson's Disease, and scenes involving a used condom, a possessed foetus, and a slithering turd, Ghost Killers vs. Bloody Mary is a Brazilian horror comedy that aims for Peter Jackson-style bad taste splatstick, but never achieves that lofty aspiration. There's a fair amount of blood and gloopy fluids to appease gore-hounds, but the comedy simply isn't all that funny, and any goodwill towards the film quickly evaporates.
Sadly, director Fabrício Bittar doesn't know when to quit: the silliness goes on and on, with the evil spirit possessing one person after another ad nauseum, his film becoming very tedious and eventually clocking in at a whopping 103 minutes. There's a meta gag towards the film where one of the characters explains that if they had tried the plan he suggested early on (to repeat the ritual used to summon Bloody Mary, only in reverse), the film would have been twenty minutes long. I wish.
3.5/10, rounded up to 4 for IMDb.