Green Shell

When attacked or thrown, this shell slides around the battle stage, damaging whomever it hits. The Green Shell (, Green Shell) is an item from the series.

Origin
The Green Shells made their debut in Super Mario Bros. as the shells of the green Koopa Troopas, and has become a recurring item in later Mario games. If a Koopa Troopa is jumped on, they retreat into their shells rather than be defeated altogether, which can be kicked as projectiles. If the shells are left out for too long, however, the Koopa Troopa can emerge out of its shell. The kicked shells can also pose a danger if they bounce off of a wall. Koopas with green shells will walk off ledges rather than turning around, a trait that is mirrored by their shell sliding off of ledges in Smash.

In  and in later games onward, if a Koopa Troopa is jumped on and retreats into its shell, it can be picked up, carried around. This, however, can be dangerous, as the Koopa Troopa can emerge out of the shell while carried and can damage the player holding the shell.

The Green Shells have become a recurring item in the  series and serves as the logo for the. When used, it allows the players to throw the Green Shell either directly in front of or behind them. While it only travels in a straight line, unlike its homing red counterpart, it is the more durable of the two; it can bounce off walls for some time before it breaks or hits an opponent.

As an item
The Green Shell debuted as a throwing item in Super Smash Bros.

Upon being thrown, the Green Shell will deal significant damage and knockback to opponents; however, it has a higher specific gravity than most other items, and as a result, it will fall onto the ground more quickly than other items. Unlike other items, the Green Shell will continue to move forward when it hits the ground, and it will continue to deal damage and knockback as it slides. The resulting hitboxes, however, are not as powerful as the throwing hitbox, and the Green Shell's output becomes weaker and weaker as it begins to slow down. Furthermore, opponents can immediately stop the trajectory of the Green Shell by merely jumping on it, then use it against the original wielder; as the Shell also ricochets off walls and other barriers, it is also possible for a player to hit by their own Green Shell.

If the Green Shell is not picked up by players, it will stay in place until it is hit by a damaging hitbox, after which it will begin moving with a speed directly proportional to the knockback of the hitbox. Jumping on it will also cause it to begin moving either left or right, but with relatively little movement.

In single-player modes
In Melee's Adventure Mode, Brawl's Subspace Emissary, and Smash 4's Smash Run, Koopa Troopas and Koopa Paratroopas can appear as regular enemies. Dealing enough damage by attacking them or jumping on them forces them to retreat into their shells. If the shell is left alone or carried for too long, then the Koopa Troopas will emerge out of their shells.

Unusually, the Green Shells found from actual Koopa Troopas are smaller than the actual item.

Description from the Super Smash Bros. Brawl instruction booklet
Slides along and launches foes.

Spirits
Equipping the Koopa Troopa, Turtle Bridge, or Lyle support spirits will give the player a Green Shell at a start of their stock.

Trivia

 * Initially the lines between the scales on the Green Shell were pale. Although the Green Shell's trophy in Brawl depicts it as it appears in contemporary Mario games, with black lines in-between the scales, the shell's in-game model is identical to its appearance in Melee. In SSB4, the shell's in-game model matches its trophy and has black lines.
 * Out of the three Shell items in the Super Smash Bros. series, the Green Shell is the only one to appear in every title, as the Red Shell has been missing since Brawl, and the Spiny Shell did not debut until Smash 4.
 * In Super Smash Bros., a glitch occurs when uses Mario Tornado on four shells in Training Mode, resulting in 999% damage.
 * In Brawl, characters with high falling speed can perform a technique with the Green Shell called "Shell Hopping", involving fastfalling, throwing a Green Shell downward, and regrabbing the shell in midair. The result gives the player a significant vertical boost, though the results are most apparent when used with.