A Spiny Shell, also referred to/called at times as the Blue Shell or Blue Spiny Shell, is an item that has appeared in every Mario Kart game except for Super Mario Kart, though it has taken different forms between games. The shell has a distinctive dark blue surface with spikes on top. Depending on the game, the shell may or may not have white wings. It is among the most devastating and feared Mario Kart items, and can prove the deciding factor for who wins and loses a race, as many an unfortunate victim have learned the hard way. Because of how much hate this item receives, many people consider this item to be the WORST Mario Kart Item (or at least on their WORST Mario Kart Items List).
While devastating, the Spiny Shell is not entirely unavoidable, as it can usually be avoided by using a Mushroom with proper timing, among other speed-altering maneuvers. The Super Horn, introduced in Mario Kart 8, can also be used to block the Spiny Shell from connecting.
Mario Kart 64
The Spiny Shell is first introduced in Mario Kart 64. In the game, the shell has spikes on it and travels along the ground. It is essentially a blue version of the common Red Spiny Shell. Any player outside first place can receive this item. However, the Spiny Shell is the rarest item in the game.
Once fired, the 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 karts that the Spiny Shell hits will be thrown into the air. This 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, sending them flying into a fairly long distance (enough to fling them over some barriers that normally cannot be jumped over). The shell makes a highly distinctive siren sound while traveling.
While it normally remains sliding along the track, 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. In other cases, before entering the haunted house, it can circle around the sign that says "WELCOME".
If the Blue Spiny Shell strikes an invincible racer it will be destroyed without the racer being damaged. If the leader is invisible, it will simply pass through them, 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 shell while in first place will result in it turning around to hit the thrower after its straight shot.
If a player gets a sideways Item Box, they will get a Spiny Shell each time. However, there are only two of these. One is in Luigi Raceway, where there is a balloon that will dip down with an item box hanging on the bottom. Another is in Koopa Troopa Beach, there is a large rock with a single item box on its top with a narrow ramp before it. In the Mario Kart 7 remake of both courses, this special item box is no longer present, and is replaced by a regular one in Luigi Raceway, and a single Coin in Koopa Troopa Beach.
Mario Kart: Super Circuit
The item serves the same function as in Mario Kart 64 for Mario Kart: Super Circuit for the Game Boy Advance, although the shell has a darker blue color. Like before, it makes a distinct siren sound when traveling. 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. The Spiny Shell is also easier to avoid; if the player jumps over an abyss or over a previous section in the track (like the jump in Mario Circuit 2) the shell will fall in the abyss or crash into the wall.
The impact of the Spiny Shell no longer cause the leader to crash and thrown off, instead they will spin out and stop in the spot he or she was hit. This trait is later reused for the POW Block in Mario Kart Wii and for the Spiny Shell in Mario Kart 8.
Mario Kart: Double Dash!!
In Mario Kart: Double Dash!!, the Spiny Shell is changed significantly. It is a standard item that any player in fourth place or lower can obtain. In this game, the shell appears with a pair of wings that allows the item to fly instead of sliding over the ground, which lets it skip any obstacle found in the course. The shell now makes a hissing noise as it launches.
When thrown, the shell flies at incredibly fast speeds 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, then charges straight into it. Double Dash!! is the first game where the Spiny Shell explodes on impact and throws the racer up into the air, also causing their kart to backflip. The blast is similar to a Bob-omb, and it can leave racers itemless if they're thrown into the air, but it's colored blue and somewhat larger. This trait is kept for subsequent games.
Other racers that are caught in the explosion will spin out and drop certain items onto 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. Additionally, once a player holds a Spiny Shell, other racers cannot receive another shell until the player has used it and hit the target. This rule is kept for later games as well.
To avoid the Spiny Shell, the player has multiple possibilities. He or she can either use a perfectly-timed Mushroom, use a Star to make the item completely harmless, or by skillfully performing a Mini-Turbo by drifting, which will sometimes cause the Spiny Shell to spin around the player and crash into a wall.
Mario Kart DS
In Mario Kart DS, the Spiny Shell has not 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 before exploding on impact, sending the vehicle thrown upwards and destroy the items held by the racer. Almost unavoidable, a player can avoid the explosion by using invincibility items like a Star, a Bullet Bill, or Boo. Tumbling as a result of getting hit by a Banana Peel or Fake Item Box will also prevent 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 makes an appearance in Mario Kart Wii for the Wii. Its function is identical to Mario Kart: Double Dash!! and Mario Kart DS, and it can be obtained if the racer is anywhere from 4th to 8th place (middle ranked positions). Its rarity is similar to that of the POW Block.
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 by passing through a Barrel Cannon, Launch Star found on Rainbow Road, or the wide ramp in DK's Jungle Parkway. It is 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. Doing a trick off a ramp at the perfect time can also result in avoiding a Spiny Shell. Also, if the player is in first when the shell is fired and drops out of that position, the shell will still attack that player.
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). This is the only time where a player can launch a Spiny Shell in first and not get targeted by it. 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 item is much rarer in Battle Mode than VS and Grand Prix modes, and only appears if there is a very large score difference between the user and the leader.
Mario Kart 7
In Mario Kart 7, the Spiny Shell has received a slight change of behavior. It is now a combination of the two preceding types of Spiny Shell- it floats in the air and homes in on the first place racer (similar to the more recent versions,) but is only slightly above the track, allowing it to smash into other players on its path (similar to the original version.) Upon reaching the first-place driver, it will float in the air directly above them and smash into them, causing a blue explosion that also harms adjacent drivers within its blast radius. Unlike in previous games, the explosion does not send players straight up; rather, it sends players tumbling sideways, which is arguably more dangerous as it opens the opportunity for a player to fall off the track much more easily than any previous incarnations, slipping them behind even more. It can also now hit players traveling through cannons in courses such as Maple Treeway or DS Airship Fortress, sending them to an unavoidable plummet with twice the coin loss and likely several drops in position. The only way to avoid this Spiny Shell is to use invincibility or speed-boosting items such as Stars, Mushrooms, and Bullet Bills, or to quickly back up as soon as the dreaded icon appears next to a player on the minimap.
Mario Kart 8
In Mario Kart 8, the Spiny Shell retains its wingless form and still have the same functions from the previous games: flying towards the first-place racer while knocking over any racer along the way (from Mario Kart 64, Mario Kart Super Circuit, and Mario Kart 7), as well as creating an explosion upon impact that spins out any nearby racers within the blast zone (from Mario Kart: Double Dash!!, Mario Kart DS, Mario Kart Wii, and Mario Kart 7). This item is unbreakable as in all of the previous games. However, the newly introduced Super Horn item can destroy the Spiny Shell. It can also be avoided with a perfectly timed mushroom boost or invincibility, as with previous games. The Spiny Shell has been nerfed in this game as it doesn't send the targeted players sky high or tumbling sideways but rather briefly stuns them on the ground. However, the Spiny Shell is still able to hit players when they are in glider mode or have exited out of a launch cannon.
- In Mario Kart 7, the Spiny Shell was originally going to have wings again (just like it's 3 predecessors) as shown in the item roulette from the demos of E3 2010 and E3 2011 however in the final version of the game, it was replaced with it's wingless form.
- In Mario And Rabbids: Kingdom Battle, the Spiny Shell is mentioned by Tom Phan.