By ADAM GRAHAM

The Detroit News (TNS)

A fantasy horror comedy that is also an Eat the Rich parable and also a functioning homage to scare classics like “Jurassic Park” and “Alien,” “Death of a Unicorn” puts forth a lot of ideas, but makes good on very few of them.

In his feature debut, writer-director Alex Scharfman pays homage to heroes like Steven Spielberg and Ridley Scott, while clearly having fun with an inventive premise: What if unicorns, the magical beings of every child’s dreams, were actually vicious, violent monsters?

But his engine runs out of steam early, and what begins as a clever comic send-up winds up hammering the same beats over and over again. This “Unicorn” dies a slow death, and the result is like sitting through an endless funeral.

Paul Rudd plays Elliot Kintner, who is on a trip through Canada with his angsty teenage daughter Ridley (Jenna Ortega, a professional angsty teenager, even at 22). He’s a lawyer for a very wealthy, high-profile figure who is looking to clean up his public image, while she says things like “philanthropy is reputation laundering for the oligarchy.”

Things are already off to a rocky start between them, an issue compounded by the fact that they’re both grieving the recent loss of his wife, her mother.

They’re driving down a remote road in the Canadian wild when BAM, their car suddenly hits something. Is it a deer, is it a horse? It turns out it’s a majestic white unicorn, and its purple blood is spilling out into the street. It’s suffering, so Elliot does what he figures is the humane thing to do, and with the aid of a handy tire iron he puts the being out of its mystery. But it’s not the last they’ll hear from this mythical creature.

They arrive at the sprawling estate of Elliot’s obscenely wealthy client, pharmaceutical baron Odell Leopold (Richard E. Grant), who is joined by his wife Belinda (Téa Leoni), his son Shepard (Will Poulter) and their butler, Griff (“Barry’s” Anthony Carrigan). The Leopolds are your typical shallow, superrich, privileged snots, the kind we’ve been trained to hate in movies, especially in recent years. Everything is suddenly heightened when that unicorn in the back of Elliot’s car, the one he thought was dead, starts making a ruckus.

What follows is a playfully over-the-top monster movie, with the unicorn’s parents arriving to avenge their fallen foal, and Scharfman lifting so directly from “Jurassic Park” and “Alien” that he’s practically pausing to wink at the camera.

But the cartoonishly garish kill scenes quickly turn monotonous, and there’s not enough going on in the story to sustain the action. There are only so many ways a unicorn horn can impale a person, and in “Death of a Unicorn” we see pretty much all of them, each one to diminishing returns.

Of the cast members, Poulter seems to be having the most fun with his role, and it’s refreshing seeing Leoni back on screen after a long absence (this is her first movie role since 2011’s “Tower Heist”). There’s simply not enough meat on this bone to make a meal, and no magic to be found in its execution.

Despite some rainbow colored flourishes, this unicorn is a dog.

‘DEATH OF A UNICORN’

■ Grade: C-

■ MPA rating: R (for strong violent content, gore, language and some drug use)

■ Running time: 1:48

■ How to watch: in theaters Friday