Sam Ballard was in a coma for 420 days after eating the slug at a party on Sydney's north shore in 2010 when he was 19.
Ballard did, and soon after he started feeling pain in his legs; the Independent notes he also started vomiting and had dizzy spells. But after swallowing the slug, Ballard contracted a rat lungworm - a parasitic worm (Angiostrongylus cantonensis) that lives in rodents and can be passed onto snails and slugs, according to the Centers for Disease Control and Prevention.
As his health deteriorated, the doctors found out that the slug probably harboured a parasite called lungworm, which nests itself in the heart of the host, causing severe health problems.
The 28-year-old's heartfelt final exchanges with his friends and family emerged as a touching obituary for the former footy player appeared in the Sydney Morning Herald.
His last words "I love you" was addressed to his mother Kathy.
Though most people experience mild symptoms and recover from the infection, it changed Ballard's entire life.
Within hours he fell seriously ill and it was later discovered that he had been infected with rat lungworm.More news: Fox News 'Does Not Condone' Hannity, Pirro Participation in Trump Rally
'We were sitting having a bit of a red wine appreciation night, trying to act as grown-ups, and a slug came crawling across here, ' Mr Galvin told current affairs programme The Project earlier this year. Many people on social media have sent and an outpouring of love to Ballard and his family, but some have not been so forgiving and believe that Ballard's friends should have stepped in. His mother, Katie Ballard, who cared for him full-time, was by his side.
However, she added, Sam's illness hit the family hard. "And then off Sam went and bang, that's how it happened".
Mr Ballard died on Friday night at the age of 29.
Katie Ballard with her son Sam Ballard pose during a photo shoot in Sydney, New South Wales on February 22, 2018.
He said: 'When I walked in, he was very very gaunt, and there were cables everywhere - it was a big shock'. Katie Ballard, Sam's mom, thought her son would eventually regain his motor functions.
And she insisted that her son was "still the same cheeky Sam, and laughs a lot". "It's huge. The impact is huge". An initial allocation of care as part of the government's National Disability Insurance Scheme saw the family receive $471,000.
Last September, without warning, the NDIS texted Ms Ballard to say a review of his plan had slashed his allocation to around £75,000.