The ROFLcopter is a joke filler that first appeared in the episode YouTubers. Marshmallow was riding it near the end. It is the first helicopter in the series. It only appeared in the episode YouTubers.
Microsoft Sam, a text-to speech voice in Windows XP, is known for making the noise of the ROFLcopter, which, when someone types in "soi" he makes a noise similar to a helicopter blade.