Artwork from Mario Kart Wii.
A Blue Shell is an item featured in multiple Mario games that has varying abilities depending on the video game. In the original title (Super Mario World for the SNES), its only distinct purpose was giving any Yoshi the ability to fly for a short time when eaten.
In the Mario Kart series, Blue Shells are arguably one of the more preferred items and for the victim one of the most annoying. Rather than being just regular Koopa Shells colored blue, they feature spikes and, more recently, have wings as well. When thrown, it'll head towards the racer in first place and attack them. In the earlier titles, the Blue Shell would not only attack the person in first place, but would also plow through any enemies in front of the racer who threw it. Recent titles have implemented ways in which you can dodge the Blue Shell.
In Super Mario Strikers and its sequel Mario Strikers Charged, Blue Shells would freeze opponents on impact, though they would not home in on them as Red Shells are capable of doing.
Blue Shells also appeared in New Super Mario Bros. where they could actually be worn by Mario or Luigi. They would also allow the user to travel faster than before and ram into enemies just as a kicked shell would do. The user would be able to permanently kill several enemies that wouldn't be able to be permanently defeated before without the help of a star, like Dry Bones, Giant Dry Bones, Thwomps, and Wigglers, to name a few. The blue shell also gave the user better underwater agility and immunity to enemies and spikes as long as the user was tucked in the shell.
See also
- Shells - Other types of shells, most of which are from the Mario game series.