A walking shell is the most common variety of shell, and is found in various levels in Rayman 2: The Great Escape and the Game Boy Advance version of Rayman 3. They are small, yellow, explosive, rocket-like, two-legged robots used by the Robo-Pirate army to guard passages. They share some behavioural traits with both dogs and horses. They chase Rayman if he passes into their line of sight, but, unlike red shells, he can tame them by running from them until they grow tired. Rayman can jump onto the backs of tired walking shells and ride them to overcome otherwise impassable obstacles. In some locations, Rayman encounters shells that are already tired or sleeping; these do not need to be tamed, and can be ridden immediately.
Rayman can make the shell jump (by pressing the Jump button) or accelerate (by pressing the Attack button). Walking shells have the ability to run over some damaging surfaces, such as [[Nettle|nettle]s and lava, but not over deep lava or water. They also appear to have some ability to stick to surfaces, and can run up steep slopes, and even fully upside down, as long as the surface is smooth and the change of angle is gradual. However, hitting a wall head-on causes them to explode. When a shell explodes, it can take out certain enemies and doors blocked by metal sparadraps, similarly to kegs.
In Rayman 2 and Rayman Revolution
- Walking shells are first encountered at the Menhir Hills, where Murfy explains to Rayman that they may be tamed. There are three shells in this level, each residing in a small doghouse. Once tamed, the shells take Rayman over patches of nettles and through a forest of menhirs that is located behind a very steep slope.
- In Rayman Revolution only, a walking shell (referred to by the Teensies as 'missile') appears in Globox's House, at the entrance to the Menhir Hills, after Rayman completes that level. Rayman can ride the shell up the mountain and destroy the avalanche that blocks the entrance to the Canopy.
- In Whale Bay, a walking shell is spawned by a generator once Rayman activates the switch that frees Carmen the Whale. Rayman can ride the shell to a door protected by a sparadrap and destroy it, opening the way to a cage.
- In the Sanctuary of Stone and Fire, a walking shell helps Rayman out of the first temple, taking him over a lava-covered passage and a 360-degree loop.
- Rayman encounters the last walking shell in the game in the Iron Mountains, where it helps him free the Baby Globoxes from the Reformatory for Disturbing Children, in the process climbing walls and beams at various angles to the ground, sometimes vertical or upside down.
In Rayman 3 (Gameboy Advance)
- In the Prickly Passage, the shells are referred to as "walking missiles" by Murfy, who explains Rayman how to ride them. Rayman rides the shells across thorny passages and 360-degree loops, jumping over many pits along the way.