The Blowfish resembles a completely round long-spine porcupinefish with light blue skin, a white underbelly dotted with spots, black beady eyes and a round mouth.
In gameplay, the Blowfish is used to slow opposing racers during a race. When deployed as a mine, the Blowfish inflates and when it hits another racer it will explode and slow him/her down. When used as a projectile, it will travel along the track and rebound off curves for a bit or until it hits another racer, though slowly. Other weapons can deflate the Blowfish without being forced to slow down.
The Blowfish is one of the hardest Pickup items to deploy, as it requires precision to use it effectively on the track. It is also slow to deploy and takes time to activate after being fired. To use it to the full extent, the player can place it behind Dash Panels or Tokens, and during drifts. Akin to the Firework, firing it forward at a bad angle may cause it to rebound and hit the one who initially fired it.
In the Japanese version of the game, the item is replaced with the Hindering Jelly (おじゃまぷよ,Ojama Puyo?) from the Puyo Puyo franchise (which was published by Sega), a large round jelly-like object with a pair of googly eyes; despite its different appearance, it functions the exact same.