1. something completely ridiculous 2.an expression signaling frustration and disbelief, often in response to an absurd event or statement. to add emphasis, interject vulgarities in the phrase, such as "snakes on a motherfucking plane"
Person #2: WTF?! Snakes on a Plane?!?!
or, more commonly:
Person #1: I can't believed we paid $8 to see that POS movie.
Person #2: Yeah, Snakes on a Plane! (waves fists menacingly, growls)