larva (n.) Look up larva at Dictionary.com
1650s, "a ghost, specter," from Latin larva (plural larvae), earlier larua "ghost," also "mask;" applied in biological sense 1768 by Linnaeus because immature forms of insects "mask" the adult forms. On the double sense of the Latin word, Carlo Ginzburg, among other students of mythology and folklore, has commented on "the well-nigh universal association between masks and the spirits of the dead."