Larva
WordNet
noun
(1) The immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose
WiktionaryText
Noun
- A stage of growth for some insects, in which they are wingless and resemble a caterpillar or grub after hatching from their egg
- An animal in the aforementioned stage.
- A form of a recently born or hatched animal that is quite different from its adult stage.
Usage notes
Although the plural is somewhat common, it is regarded by some as incorrect.