The Spiny Shell (often referred as the Blue Shell, Blue Koopa Shell, or Spiny Koopa Shell) is an item that has long featured in the Mario Kart series, and was first introduced to it in Mario Kart 64 in 1996. It had recently been included in the Super Smash Bros. series as well.
Widely considered to be the most infamous item out of all in the Mario Kart, this item would target the driver in first place with great speed, and then explode onto them to pummel the unfortunate driver in to the air. Hence, it provides an almost unavoidable challenge for winning drivers to contend with due to unpredictable spawns from the Item Boxes, and can dramatically change the outcome of races.
The Spiny Shell is a blue-coloured shell built in the same image as other shells in the Mario series, but features a multitude of sharp white spines protuding from the top layer, giving it its 'spiny' name. It also gives the shell an appropriately intimidating appearance, reflecting the powerful nature of the item's purpose and impact.
Whilst the shell has consistently maintained its blue colouring and spiny appearance over the many Mario Kart games it has appeared in, one aspect of it that often varies are the wings - which enable the shell to soar over the track. They were introduced on the shell's design in Mario Kart: Double Dash!! and included in the next two kart games, but were dropped in the shell's latest iteration with the advent of Mario Kart 7 in 2011.
Mario Kart series
Mario Kart 64/Mario Kart: Super Circuit
The item had originated in Mario Kart 64 where it made its first appearance. It was the rarest item in this game, with the least frequent spawns from the Item Boxes. When activated, the shell initially zooms forwards in a straight line then speed forward along the ground to track down the driver in first place, and generate a loud siren noise in the process as a warning. Whilst it would only target the winning driver, other drivers could also be knocked away by the item if they got in its way. When it reaches its target, the shell proceeds to explode onto the unlucky driver and blast them high into the air.
In this game, the shell can be held behind the driver that obtained it, much like the regular Green and Red Shells, but can only be tossed forwards. Care must be taken when launching it however, as the shell can be destroyed when collided onto a wall or an obstacle.
To avoid the Spiny Shell, the driver can use Boo to make themselves invisible from the shell's sight. However, this technique will only delay the dreaded fate of being hit, as in this case the shell will simply make another lap of the circuit to track down the first driver again.
The shell functioned in the succeeding Super Circuit game in pretty much the same way as it did in MK64.
Mario Kart: Double Dash!!
The Spiny Shell had received a cosmetic makeover in this game, with the addition of wings that enabled it to soar over the circuit to track down its target more quickly. Since it flies in the air, other drivers can't be effected. As usual, the shell carries out its purpose of exploding onto the first-place driver and send them flying - this time, with an even more destructive blast radius; the drivers just behind the leading one can get caught in the radius to join the pummelled driver as well. Items held by the victim will also be destroyed.
One way of avoiding the blue blast is to pull off a Mini Turbo at a precise moment as the shell makes its descending plunge - if successfully pulled off, the shell will end up blasting onto the floor.
The item has more or less remained the same In the next two editions of Mario Kart, retaining its wings and carrying out the same function of soaring over the course to track the driver in first place and explode onto them. It is obtainable in middle-ranking positions.
Like the Double Dash!!, there are a multitude of methods available to escape the otherwise unavoidable fate of being pummelled by the blue shell. As well as obvious ways like mushrooms or stars, a common technique to avoid being hit is to immediately slow down and let the driver(s) you're ahead of overtake you, as soon as the shell is released - this is particularly easy to detect in the handheld DS version, which displays all the racers' rankings and items on the lower screen. Flying off from cannons or giant ramps located in some Wii tracks will also prevent the shell from being able to reach up with its target.
Alternative ways to avoid it include hitting any obstacles like Bananas or Fake Item Boxes (particularly effective with the latter in DS), just as the shell arrives to plunge into the driver. Whilst the driver would still get harmed of course this way, collision with these obstacles will nullify the far more damaging effect of being exploded into the air, sparing the driver from it.
With regards to red vs. blue team races that can be played in both versions, in the DS game the shell will always attack the driver in first place, regardless of whose team the leading driver is in. However, this issue has been resolved in the Wii game as with the rest of items; the shell will instead attack the leading driver of the opposing team only, even if they're not in the first place.
Mario Kart 7
From Mario Kart 7, the shell received a new makeover paying close homage to the original iteration introduced in Mario Kart 64, with wings being dropped. Like the original, the blue shell once again slides along the ground at quick speed - posing an additional hazard to the rest of the drivers in the pack as they can also be knocked over if they get in the way. Like the previous games, it's still obtained in the lower middle-ranking positions, roughly from seventh to fourth.
What has also changed is its explosion unleashed on the first driver; instead of violently tossing the victim up into the air, they become knocked away sideaways, possibly into bottomless pits if they're especially unlucky. Items and three Coins - which feature heavily on tracks in this game - will also be dropped by the racer. As the game features gliding sections throughout the courses, the shell can be especially devastating if the first-place driver happens to be unlucky enough to be gliding over a bottomless pit at the time of the shell's arrival.
Mario Kart 8/Mario Kart 8 Deluxe
The Spiny Shell has been mostly unchanged for the Mario Kart 8 and the Deluxe remake, although with a few modifications. The explosion from the shell is somewhat weaker than before, as the victim won't tumble sideaways after the attack, and the shell can be more easily dodged with well-timed use of a mushroom boost. And of course, it can be destroyed by sounding a super horn item.
Super Smash Bros. series
Super Smash Bros. Brawl
In Super Smash Bros. Brawl, the Spiny Shell is featured as a sticker that boost the launch power of any fighter that has it equipped by 11.
Super Smash Bros. for Nintendo 3DS/Wii U
The Spiny Shell is featured as both an item and a trophy in Super Smash Bros. for Nintendo 3DS/Wii U. When thrown, the Spiny Shell targets the current highest-ranking opponent of the thrower. In a time match, it targets the player with the most points; in a stock match, the one with the most stock. In a Coin match it targets the one with the most Coins. If multiple opponents are tied, it will target the one with the least damage. If this is also tied, the one closer to the thrower will be targeted. When launched, it will float over the target for 5 seconds before slamming into them, which creates an explosion. The Spiny Shell also damages characters who touch it while it is flying. The shell can be avoided if the player hide themselves under a solid platform.
- NA: "The devastating blue Spiny Shell that normally appears in the Mario Kart series. This shell seeks out the lead racer and ruins his or her day. In Smash Bros., it will hover above one of the fighters before crashing down and exploding. Avoiding the impact can be challenging."
- EU: "In the Mario Kart series, these blue shells play a big role, tearing down the track at a frightening speed before crashing down on whoever's in first place. When thrown, it'll hover around above a fighter's head, and after a short while drop down and blow up. If you find one targeting you, get ready to dodge that explosion!"
Super Smash Bros. Ultimate
The Spiny Shell returns as an item in Super Smash Bros. Ultimate. It is nearly identical to its past appearance, but since Coin battle was removed, the information pertaining to the way it target enemies in this mode no longer apply.