Spiny Shell (blue)

The Spiny Shell (also commonly referred to as the Blue Shell) is an item from the Mario Kart series. It's first appearence is in the game Mario Kart 64, where it was known as the Blue Spiny Shell.

The Spiny Shell has appears in many Mario Kart games, being an obtainable object by taking an Item Box. Its general purpose is similar to that of a Red Shell, except for that it targets the player in 1st place. Of course, its function may vary slightly regarding to the game where it appears. Aside the Mario Kart games, the Spiny Shell is a power-up in some Mario sport games.

Mario Kart 64
The Spiny Shell is first introduced in Mario Kart 64. In the game, the shell had various spines over it and traveled along the ground. It was essentially a blue version of the common Spiny Shell and named here Blue Spiny Shell. Any player outside of first place could receive this item, but it is the rarest item in the game.

Once fired, the Blue Spiny Shell will travel straight forwards for a second or two. If it hits an obstacle during this time it will be destroyed, so care must be taken to avoid wasting it. After a few seconds the shell will begin traveling along the ground, following the track ahead of the shooter. Any opponent or item in its path is destroyed - it can be avoided by moving out of the way, as it will not target anyone except the leader of the race. Once it gets to the leader, it will crash into them and disappear, launching them a pretty good distance while flipping over (enough to fling them over some barriers that normally cannot be jumped over). The shell makes a highly distinctive siren sound while travelling.

While it normally remains grounded, the Spiny Shell will take to the air if required to continue its chase, soaring over gaps and jumps. A particularly strange case occurs on Banshee Boardwalk: the shell will fall off the edge of the track just before the house, resulting in it making a corkscrew flight to get back on.

If the Blue Spiny Shell strikes an invincible player it will be destroyed. If the leader is invisible, it will simply pass through, though it may then simply make another lap of the course and hit them afterwards.

The shell can be dragged behind a kart like other single shells. In this position it will destroy any opposing items it touches, as well as cause opponents to crash. It cannot be fired backwards.

Using the Spiny while in first place will result in the shell turning around to hit the thrower after its straight shot.

It should be noted that in Luigi Raceway, there is a Luigi Balloon that will dip down with an item box on the bottom. Also in Koopa Troopa Beach, there is a rocky hill with a lone item box on its apex with a narrow ramp before it. If players get these item boxes, they will always get a Spiny Shell.

Mario Kart: Super Circuit
The item serves the same function in Mario Kart: Super Circuit for the Game Boy Advance, although the shell has a darker blue color. When shot, it makes a distinct siren sound to alert those ahead that the shell is coming. Like the Red Shells in the game, it can be dropped behind the player and will activate only if the kart in the first position passes directly by it.

Mario Kart: Double Dash!!
In Mario Kart: Double Dash!!, the Spiny Shell was changed significantly. It is a standard item that any player could obtain by running over an Item Box or even a Double Item Box. From this game, the shell appears with a pair of wings that allows the item to fly instead of sliding over the ground, which allows it to skip any obstacle found in the course. The shell now makes a hissing noise as it travels.

The item is only given to the racers that are in fourth place or lower. When thrown, the shell flies at incredible speed to the current head racer, bypassing all of the other positions. After finding its target, the shell hovers behind the vehicle to home in on it and explodes on contact. The impact causes a blue explosion (similar to a blast from a bob-omb) and throws the player up into the air. Other racers near to the leader would also be blown up by the blast or spun around a bit after the impact. The blast will also cause all the items held by the player to drop to the road while destroying any items already on the ground.

The Spiny Shell always goes for the leading player in the race (even if it is the shooter). Therefore, if the player in first already crossed the finish line, any Spiny Shell shot after that point will go to the active leader of the race (in this case the second place racer). Thus, once the player in second crosses the line, the shell will target the player in third, and so on and so forth. Additionally, once a player holds a Spiny Shell, other racers cannot receive another shell until the player has used it and the item has exploded over its target. This rule is kept for later Mario Kart games.

Mario Kart DS
In Mario Kart DS, the Spiny Shell hasn't changed since its redesign in Mario Kart: Double Dash!!. The Spiny Shell works in the same manner as in Mario Kart: Double Dash!!. It is obtainable from fourth to seventh place. Once fired, a Spiny Shell flies following the road to reach to the leader. Once locating its target, the shell flies around briefly over its target and falls over the vehicle, creating an explosion to send the vehicle flying and destroy the items held by the racer. Almost unavoidable, a player can avoid the explosion by using items like a Star, a Bullet Bill, or Boo. Tumbling as a result of getting hit by something like a Fake Item Box will also prevents the damage received by the explosion. Finally, the shell can be avoided by skillful use of a Mini-Turbo; karts with a high handling (Like the Dry Bomber) can do it by a timed hop right after releasing the Mini-turbo.

Mario Kart Wii
The Spiny Shell made an appearance in Mario Kart Wii for the Wii. Its function is identical to Mario Kart: Double Dash!! and Mario Kart DS, and can be obtained if the racer is in third place or lower. The item is rather more common in this game compared to previous games.

If a player is targeted for attack by a Spiny Shell or is in the vicinity to be hit by the blast, the player can avoid the attack by means of a Star, Mega Mushroom, Bullet Bill, well-timed Mushroom, or Barrel Cannon. It's even possible to drop a Banana at a very precise time during the drop after a jump, which causes the Banana to collide with the shell and spare the target.

In team play, the Spiny Shell will aim for whoever on the opposing team is farthest in front, ignoring and not damaging anyone on the user's team (so it will target the racer in fourth if the first three racers are on the user's team). For the first time, the item is also available in Battle Mode, flying straight to the opposing team's highest-scoring player after a short delay. The shell is much rarer in Battle Mode than Versus Mode, and only appears if there is a very large score difference between the user and the leader.

Mario Kart 7
The Spiny Shell makes its appearance in Mario Kart 7 as a mix of its grounded and winged forms from previous games. Like its older incarnation, it lacks wings and travels along the ground when launched, striking everything in its way, it will fly across large gaps and automatic travel points if required, and it its rarity is on par with the Thunderbolt. It also keeps some of its newer properties: it cannot be dragged behind the user's kart, and once it gets to the leader, it will hover overhead and crash down in a blue explosion. All of the racers hit by the shell drop Coins, but those hit by the explosion may also lose the items that they were dragging behind. Unlike in Mario Kart Wii, the racers in the front hit by the Shell's explosion don't rise from the ground by the impact and instead they roll over uncontrollably, costing several seconds for the driver to recover. The Spiny Shell cannot be avoided unless the player use a Mushroom, a Star, a Bullet Bill or dropping out of 1st place before it is launched. The Shell's size is bigger than Green and Red Shells and bigger than the Spiny Shells in previous Mario Kart games. In DS Waluigi Pinball, DS Airship Fortress, and Wii Maple Treeway, Spiny Shell is much more dangerous, as they can potentially cause the player to fall into the gap, during the launch.

Mario Hoops 3-on-3
In Mario Hoops 3-on-3, the Spiny Shell is known as "Angel Shell", and its appearance is like it looked in Mario Kart 64. The Spiny shell is a homing projectile that once thrown, chases a player of the opponent team and explodes upon contact of the target, in a similar fashion to a Bomb.

Mario Superstar Baseball
The Spiny Shell appears as an item in Toy Field. It steals 50 coins from the leader and gives them to the user.

Trivia
In Mario Kart 7, Spiny Shell also made warning siren when it was coming near leader driver.