10 Best Sibling Rivalries In Horror Movie History

10. Casey And Barto - The Unborn

Released in 2009, David S. Goyer's The Unborn was patently just an excuse to stare at star Odette Annabelle's (then Yustman's) ass.

So shameless was the film about its use of the male gaze, that they even slapped the actor's butt on the poster. The story that they did manage to squeeze in between gratuitous buttock shots? The simple tale of a girl, possessed, by her own dead brother, and the men who attempt to help her.

Unborn Barto is the spirit of Casey's (Annabelle) twin, who died in the womb, and is none too happy about it. A plan is hatched to exorcise the brat, who turns out to be more stubborn than anyone might have imagined.

The Unborn is fairly unmemorable - Drag Me to Hell lite - but it's entirely worth a go-round for the antagonistic relationship between Casey and Barto. Eventually, Barto is vanquished, but not without a fight. The movie culminates in a surprisingly great exorcism sequence, enlisting Gary Oldman and Idris Elba to help rid Casey of her dark passenger.