Spicebush swallowtail caterpillar (Papilio troilus), in the Dismal Swamp National Wildlife Refuge, Chesapeake, Virginia.

This caterpillar is a convincing miniature mimic of this swamp creature. When disturbed the caterpillar extends a forked organ called an osmeterium from its mouth parts, to further the snaky illusion. It also releases a foul odor to deter predators. You can see video of this behavior by clicking here, including sounds of the choking cough of the filmmaker when the scent is deployed. 

My photo of an adult spicebush swallowtail butterfly can be viewed here. And you can click any photo in this set for enlarged views. 

Spicebush swallowtail caterpillar (Papilio troilus), in the Dismal Swamp National Wildlife Refuge, Chesapeake, Virginia.

This caterpillar is a convincing miniature mimic of this swamp creature. When disturbed the caterpillar extends a forked organ called an osmeterium from its mouth parts, to further the snaky illusion. It also releases a foul odor to deter predators. You can see video of this behavior by clicking here, including sounds of the choking cough of the filmmaker when the scent is deployed. 

My photo of an adult spicebush swallowtail butterfly can be viewed here. And you can click any photo in this set for enlarged views.