The plunger was the rabbids' weapon of choice in the first three Rayman Raving Rabbids games. It could be used as a gun in the FPS games. The plunger was later replaced by the toilet brush for unknown reasons.
Plungers also appear in the TV series, where they are used by the Rabbids for a variety of purposes such as weapons, tools, or for just playing around. Lapinibernatus uses a plunger-like device to power his Time Washing Machine and TV Time Machine. Thief Rabbid is shown to have an obsession with plungers and even has plungers that contain hidden weapons/devices.