Archie the Catapillar Soldier
From Bernard Perier’s Zkwyx Meccanaut book.
Archie is a Caterpillar Soldier from the planet Loonia (also encountered by Zkwyx on his travels). Archie is powered by an MR motor, and works in the same way as Grubby — though, in this case, the model goes up and down instead of side to side. The ratchets here are on the front and rear axles — as Archie’s middle rises, the rear wheels move forward and as he falls, the front wheels roll forward.