A 10-minute, low budget horror short by Australian director, Jennifer Kent, called The Monster. Pretty effective in a short amount of time.
Seems like a dry run for her upcoming feature, The Babadook, due out in November. (I'd guess the feature film goes in a different direction than the short.)
The ever-reliable Noel Murray, one of the critics at The Dissolve (and formerly of The AV Club), called The Babadook one of the best films he saw at Sundance this year.. He also said:
On an intellectual level, I could tell you that what makes The Babadook so brilliant is how it ties its scares to something real, and more deeply frightening than any boogeyman: namely the loss of a spouse, and the fear that an unusual child will become a lifelong burden. But none of that would matter (much) if The Babadook didn’t work so well on a visceral level. Simply put: This movie is absolutely terrifying...
Anyways, the short film seems to work pretty well, IMHO. Worth 10 minutes of your time.