9. Mauled By A Merman - The Cabin In The Woods
In Drew Goddard's delicious horror-satire The Cabin in the Woods, Steve Hadley (Bradley Whitford) is one of the control room technicians responsible for operating the central ritual.
Hadley expresses a deep desire to see the Merman show up as one of the ritual's selected monsters, given that he's never seen the creature, and in the film's insane climax he most certainly gets his wish.
When the heroes press the "purge" button which releases the incarcerated monsters into the facility, a wounded Hadley finds himself coming face to face with the Merman, which slithers out of the darkness to Hadley's fascination.
After a few beats of staring at the monster, though, Hadley snaps back to reality and quips with frustration, "Come on...," noting the irony that his first sighting of the Merman will also be his last.
The Merman then makes short work of Hadley, mauling him and spraying his gory remains through its gills like a geyser.