The venomous caterpillar also known as the puss caterpillar is Megalopyge opercularis. Its soft, fur-like covering hides venomous spines that can cause intense pain when they touch human skin.
The species is the larval stage of the southern flannel moth. Its long hairs make it resemble a tiny furry animal, which likely inspired the name “puss caterpillar.” The caterpillar can vary from pale gray or golden brown to dark charcoal, sometimes with a bright orange stripe.
Contact may produce immediate burning pain, swelling, a rash, blisters, nausea, headache, or pain that radiates along the affected limb. The condition is called erucism, or caterpillar envenomation. Sticky tape can help remove embedded spines, but severe symptoms require medical attention.
Saddleback caterpillars are also venomous, but they belong to a different group and have a distinctive saddle-like marking. Cecropia and gypsy moth caterpillars are not the species referred to by the common name puss caterpillar.