Powder Gag
An old one dating from theatrical cartoon shorts, practically Self Explanatory. Take a powder, any powder, circumstances (a sneeze, a fan, a hairdryer, a Practical Joke or even spontaneous explosion) causes it to be blown all over the place. The camera goes blank for several seconds, turning the color of what has exploded.
When the dust clears and we see the characters again, they and their surroundings are completely, utterly covered in the stuff. They stand stiff and still, often trying to get the stuff off their eyes. Then one makes some sort of a joke before the scene cuts away. Hilarity Ensues if the character is confused for a ghost or some other monster.
When liquids are involved (e.g. in a Bucket Booby Trap, the result is usually Covered in Gunge.
- Shows up in Lord of the Rings, if you can believe that. Will Whitfoot, mayor of Michel Delving and the fattest hobbit in the Shire, is caught in the collapse of the Town Hole and emerges covered in chalk, thus earning the nickname "Flourdumpling". It happens off screen—er, off page—but still, there you are.
- The Ed, Edd 'n' Eddy episode "In Like Ed" featured this gag, produced by a baking powder smoke bomb shaped like a jawbreaker.
- "Smile For the Ed" had Ed shouting "Makeup!" and poofing Eddy through the wall with a chalkboard eraser. The episode ends with him doing it to himself, producing this trope.
- The nuclear cheese blast in Over the Hedge.
- The coke-sniffing scene in Annie Hall.
- Scooby Doo has done this more than once, at one time this was the complete disguise for the villain of the week who covered himself in flour. Must have been very convincing because when Shaggy and Scooby get covered in the stuff he thinks they're ghosts.