Octowashers are obstacles found in the Octo Expansion and Return of the Mammalians. They are Octarian machines, composed of two circular fans placed horizontally one over the other, with a spinning torrent of ink between them. The top fan has two lamps that resemble eyes, similarly to Flooders. Stationary Octowashers dimly flash orange while moving ones flash yellow. Octowashers are completely indestructible.
Octowashers are usually found on or near ride rails and most of them are stationary, though a few move along rails towards the player. Touching them immediately breaks the player's armor or splats them if they have no armor, and also knocks them off any ride rails they were on (usually causing a splat from the resulting fall).