Owlet moth caterpillar (Noctuidae: Noctuinae: Phosphila sp.) from Monteverde, Costa Rica.
Giant swallowtail caterpillar, Papilio cresphontes, from Monteverde, Costa Rica. When threatened, they are capable of inflating tiny 'horns' called osmeteria (singular osmeterium) that give off a strong unpleasant odor.
