1. A rocket launcher
2. A helicopter
But also can be used for fun.
Helicopters make a soi soi soi kinda noise so saying pharses like the one in the example explains it, the rofl is added on just to make it seem kiddish and funny.
Armenants of the Roflcopter:
1.Roflamomissles:Most powerful missle ever
2.LMAO Missles:Standard Roflcopter missles
3.lolRockets:Small weak rockets
4.LoLer Cannon:Its just a big machine gun
5.F-Bombs:Use these if you want to quickly silence the place
6.Lmaolemons:is fuel for roflcopter
A sex position, where a women lies down doggystyle with her face and chest on the bed while arching her back. The man inserts his penis and proceeds to do 360 spins, using his hands to balance and spin himself on her ass keeping his legs in the air. All while instertion is still fully fledged. Thus, simulating the propeller blade on top of a helicopter.
STEP TWO: Start moving your legs in a forward direction, as if to walk, making sure your shoes catch enough of the floor to turn in the desired direction.
STEP THREE: Keep repeating step two until point is taken.
------When to do it-----
When something sends you into histarics you may proceed to roflcopter
Also said as
And way more
Person 2: "lolwut, how?"
Person 1: "I threw a flaming hamburger at his house"
Person 2: "ROFLCOPTER"