That was the dare facing 17-year-old Liam McGuigan on a school footy trip on Queensland's Sunshine Coast. His response: "It won't kill me."
Liam picked up a slug, put it in his mouth and swallowed it. He now realises how incredibly lucky he is to be telling his story, particularly this week, after a Sydney man died from doing the same thing.
In the days that followed Liam's dare, the Year 12 student started feeling lethargic. His muscles stopped working.
"I went to hospital and they thought it might be my appendix. So they took that out," he tells news.com.au from Brisbane.
Doctors were wrong. Within hours he was in the back of an ambulance, stripped naked, covered in ice to reduce his soaring temperature.
Liam's body was shutting down because the slug he swallowed was carrying a parasitic worm. When the slug died, the worm found a new home in his spinal cord and "basically ate its way up to my brain".
The now-27-year-old fell into a coma. Doctors at Royal Brisbane Hospital kept him in the coma for four weeks and pumped his body full of steroids. They told his mother to "plan his funeral" and that he had a one-in-17 million shot at surviving.
"When I went in, I weighed 85kg. When I came out of the coma, I was 38kg. My thigh looked like my wrist, just skin hanging off it," Liam says.
"I had to learn how to eat, speak, walk, everything all over again. I knew how to do it but getting my brain to tell my body how to do it was another thing."
Staff scribbled the alphabet on a whiteboard at RBH alongside the words "yes" and "no". For weeks Liam would communicate that way. If he wanted water, or the television, or the toilet, he had to spell it out.
Speech therapy followed for four months and Year 12 went out the window. He would eventually repeat, get his certificate, and regain "99 per cent" of his former life.
This week, he was reminded again how lucky he is.
Sam Ballard, 29, died on Friday surrounded by family in Sydney's north, eight years after he ate a slug as a dare.
Mr Ballard contracted the same disease — eosinophilic meningo-encephalitis — and spent 420 days in a coma. When he woke, he had an acquired brain injury that meant he needed 24/7 care and could not feed himself.
"We were sitting over here having a bit of a red wine appreciation night, trying to act as grown up and a slug came crawling across here," Sam's friend Jimmy Galvin said.
"The conversation came up, you know. 'Should I eat it?' And off Sam went. Bang. That's how it happened."
When news broke that Sam had passed away, Liam's phone lit up with messages from friends thankful that he didn't suffer the same fate.
"All my friends and family saw Sam's article and tagged me in it," Liam says. "I think about it all the time. That could've been me."
These days Liam is a happy, healthy house painter. He's recently married, too. His message is simple: "Hugs not slugs."
"It was stupid but I didn't think it was dangerous," he says. "Being 17 years old, you do stupid things. I'm lucky."
Both Sam and Liam ate slugs that were carrying rat lungworm. The worm is usually found in rodents but molluscs that eat rat excrement can also become infected.
The NSW Government's Department of Health fact sheet reveals that symptoms vary from patient to patient. Some people develop no symptoms, others can have mild, short-lived symptoms.
"Very rarely, rat lungworm causes an infestation of the brain. People with this condition may have headaches, a stiff neck, tingling pain in the skin, fever, nausea and vomiting."
The department advises simple measures to avoid the disease include never eating raw snails or slugs, supervising infants around the garden, washing vegetables and lettuce and washing hands after gardening.