Tiger Swallowtail Caterpillar Everted Osmeterium crawl on wood

This is a Tiger Swallowtail Caterpillar. It will eventually become an adult Tiger Swallowtail, a large yellow and black striped butterfly. This one has everted its osmeterium, the forked organ that emits a foul odor, acting as a defense mechanism when the caterpillar feels threatened. Brown caterpillar crawl on wood. Background music added.