The appearance and coloring of caterpillars can vary widely, although most have tubular, segmented bodies with three pairs of true legs and ten abdominal segments. They can also have up to four pairs of prolegs -- fleshy, stubby little structures coming out from the middle of the abdomen.
As a rule of thumb, the more colorful and fuzzy a caterpillar is, the more likely it is to sting if touched.
Not all caterpillars look strange -- but some appear to have come from another planet entirely. Here are some of the most bizarre caterpillars around.