Green Lacewing larva: order Neuroptera, family Chrysopidae, from Iowa. Also referred to as "aphid lions," these larvae are ferocious predators of aphids and their eggs.
Owl butterfly caterpillar (genus Caligo) from Belize.
In addition to mimicking each other and surrounding foliage, some insects (like this caterpillar from Belize) have evolved to mimic bird droppings, a phenomenon known as mimesis.
