Megalopyge opercularis. The furry pus caterpillar. An asp. Donald Trump’s alleged toupee. Whatever you want to call it, one thing’s for certain: It packs a punch so powerful it could send you to urgent care.

While asps may have been in the South for ages, recent commentary on a certain presidential similarity have brought them back into the spotlight: Some may say they look like Donald Trump’s hair sprouted legs and walked right out of the White House.

While that’s certainly up for interpretation, offers some sound advice: “If it looks like The Donald’s hair, leave it alone.”

Austin resident Drew Lintz recounted his recent caterpillar run-in with KVUE.

Lintz said he was on his way to Barton Springs, threw on his swim trunks from a bag he had sitting outside and went on his way. Moments later, he experienced pain so severe it stopped him in his tracks.

“Seriously the most pain I’ve ever felt from an insect bite,” said Lintz. “I wouldn’t wish that on anyone.”

Lintz said that when he shook out his swim shorts, a hairball about an inch-and-a-half in length plopped out. Upon further observation, he noticed a welt above his left knee and that the hairball was actually a live caterpillar.

He described the pain as coming in what felt like “heat waves,” and within 30 minutes it seemed the pain had traveled up to his kidneys. He mentioned that in the process, he also brushed the hairy caterpillar with his pinky finger, saying the pain from that particular contact had spread all the way up to his shoulder.

After further research, he and his girlfriend decided he needed to seek medical attention.

“My pinky felt dead and I had pain to the bone,” he said. “I went to urgent care, got a shot in the butt and it laid me up for the evening. The people behind the counter were laughing at me.”

However, in certain cases, a sting from the furry pus caterpillar is no laughing matter.

“In general, you wouldn’t consider it a medical emergency, but there are plenty of cases of people going to the doctor because of its stings,” said Ben Hutchins, an invertebrate biologist with Texas Parks & Wildlife.

In fact, Hutchins said people with pre-existing conditions can experience more serious symptoms like blisters, stomach cramps or even heart palpitations.

Hutchins added that many have no need to worry about the caterpillar, which at adulthood becomes a Southern flannel moth, because it’s highly unlikely to reach the “plague proportions” of insects like crickets or grasshoppers.

He reported that while asps aren’t necessarily uncommon, they aren’t seen too often around Austin. Though if you want to be wary, Hutchins mentioned they like to hang around in woody plants, shrubs and trees and are prone to fall onto passersby.

While generally orange in hue, Hutchins said it’s those wispy hairs that have the ability to sting.