Blastworm

Blastworms are the larva of Stagnox in The Legend of Zelda: Spirit Tracks. They initially appear at the top floor of the Forest Temple, dropping from the ceiling upside-down. They are used for puzzles, and as such spawn infinitely. After they drop, they right themselves and slowly go after Link if he is nearby. If attacked, they roll into a spiky ball. After a lengthy amount of time, they blink red and explode. They also explode if attacked further or blown against a surface with the whirlwind. The player needs to use the whirlwind to cause rolled-up Blastworms to destroy blocks and activate a Crystal Switch; non-rolled ones will not work.

Later, Stagnox spawns three of them at a time during the second half of its battle. One must be blown into it when it swoops down, stunning it.