A caterpillar is a fuzzy, worm-like insect that transforms into a butterfly or a moth. Many caterpillars are striped and colorful.
A caterpillar is officially the larva, or immature form, of a flying insect — generally, a butterfly. Because caterpillars are growing rapidly, they tend to eat constantly, and for this reason they're considered pests by gardeners and farmers. The word caterpillar comes from the Old North French caterpilose, literally "shaggy cat," from the Late Latin catta, "cat," and pilosus, "hairy" or "shaggy."