Humans battle extraterrestrials in Cowboys & Aliens, which injects an alien invasion into a classic Western.
Photo: ILM/Universal Studios and DreamWorks II Distribution

Cowboys & Aliens offers irrefutable proof that UFOs exist — in genres beyond the sci-fi zone.

Jon Favreau’s PG-13 popcorn flick tells the story of 1870s pioneers in the American Southwest squaring off against ruthless extraterrestrials. Also opening Friday, energetic sci-fi comedy Attack the Block imagines a showdown between aliens and gang members from London slums, who use their street skills to battle beasts from beyond Earth.

The two very different movies join recent alien invasions of pop culture including Paul, which flipped the buddy-comedy road trip on its ear by throwing a smart-aleck extraterrestrial into the mix, and Super 8, in which J.J. Abrams grafted a space monster into a coming-of-age story molded in the Hollywood tradition of pictures like Stand By Me.

Given aliens’ infinite adaptability, it’s only a matter of time before they shift the shapes of other well-worn entertainment formulas.

Consider the possibilities for other alien-invasion mashups:

Reality TV

Working title:Big Brother From Another Planet
Contestants locked in their California bunker don’t realize it, but living among them is an extraterrestrial that has temporarily assumed human form. On a mission to study human intelligence, it reports back to the home planet: “Conquering Earth will be a piece of cake.”

Talent Show

Working title:America’s Got Aliens
They sing (in Na’vi), they tap dance (on the ceiling), they juggle multiple wormholes while doing yo-yo tricks with their tails. Rejected contestants fight back by ensnaring snobby British judges in projectile saliva and flinging them into space.

Frat Slapstick

Working title:Hangover 3: The Uranus Chronicles
Four lovable losers wake up surrounded by vomit in the hospitality chamber of an interplanetary mothership. They befriend a telepathic quadruped gifted with superior intelligence but cursed with loose bowels.

Horror Film

Working title:The Last Space Station on the Left
What happens when an ooze-dripping mutant exile armed with a photon-fueled chainsaw latches onto a stranded spaceship staffed with remarkably good-looking astronaut scientists? Chop chop.

Tarantino Twist

Working title:Pulp Basterds From Outer Space
Most sci-fi pictures saddle their aliens with crap dialog. Writer-director Quentin Tarantino would equip his profanity-spewing extraterrestrial sadists with eloquent rants that fuse the precision of a Nazi commandant with scholarly Stephen Hawking-inspired musings and a rich vocabulary featuring 37 alien variations on the M-F word.

Other Alien Mashups?

What other kinds of TV shows and movies would be improved by adding aliens? Weigh in below with your own extraterrestrial mashup ideas.

In Attack the Block, tough London youths defend their turf from aliens.
Photo courtesy Screen Gems