Mealworm

Mealworms are the larval form of the mealworm beetle, Tenebrio molitor, a species of darkling beetle. Like all holometabolic insects, they go through four life stages: egg, larva, pupa, and adult. Larvae typically measure about 2.5 cm or more, whereas adults are generally between 1.25 and 1.8 cm in length.

Alastor Moody (actually Bartemius Crouch Jr. in disguise) kept a glass box with mealworms during his tenure as Professor in Defence Against the Dark Arts.

Appearances

 * Harry Potter and the Goblet of Fire (film)