Red Shell

Red Shells are red Koopa Troopa shells that first appeared in Super Mario Bros.. Although not their first specific use, they were worn by Koopa Troopas. The Koopa Troopas wearing Red Shells were a bit more intelligent than normal green-shelled Koopa Troopas. They did not fall off cliffs and simply turned around when reaching a ledge. They are second most common shell, after Green Shells.

Similar to a Green Shell, the Red Shell will be launched when the Koopa Troopa wearing it is jumped on. In later games, they can also be held and thrown. In Super Mario Bros. 2 (which calls them "Turtle Shells"), they are the only type of shells and are found in grass rather than on Koopa Troopas.

During the events of Super Mario World, Yoshis can spit out fire while in possession of the Red Shell.

In the Mario Kart series, they can home in on the opponent whose rank is one higher than the driver's. Red shells can be picked up in singles or triples, in which case they circle around the kart until all three are fired. In this state, they can be used as a barrier, useful for blocking contact with other hazards, such as Bananas. However, they offer no protection against Blue Shell]s and [[Fake Item Boxes. If the character comes in contact with any other driver, then the other driver will be knocked over. The exception to this rule is in 'Mario Kart: Double Dash!!'', where the shells are carried rather than circle around a character's kart.

Red Shells also appeared in the Super Smash Bros. Series. They were in both Super Smash Bros. and Super Smash Bros. Melee. Unlike the Green Shell, which went in a straight path until it fell off, the Red Shell will stay on one platform, and bounce back and forth hitting anyone who hits it (including the user). They disappear over time, however. It is unknown if the Red Shell will return in Super Smash Bros. Brawl.

Trophy Information
''Throw a Red Shell, and it will home in on random characters and send them flying straight up. Red Shells moving around the surface are dangerous to all players, but they may also present attack chances for players with good timing and strategy. Red Shells won't leave the platform they're on once they start moving.''