Don Smith, 84, found the 15.4-pound puffball while walking his daughter's dog last week near Woodstock. Eager to share his discovery with the world, he asked his granddaughter Kaylie Ngo to post a photo of his find online.
She obliged, and a photo of Smith with the enormous puffball in his lap has now been shared 4,686 times.
'My 84-year-old Grandpa from Mossley, Ontario wants "the internet" to see this,' Ngo wrote on Facebook. 'He is extremely proud of this find.'
The puffball measures 20 inches in diameter.
'He's just really excited to have found something so special,' Ngo told the Toronto Star. 'He just wanted to share it with everybody. I thought it was really cute.'
But Smith won't make a dinner out of the mighty mushroom. He finds the taste of puffballs too woody and doesn't eat them.
So he gave his precious find to a friend - but believes it will probably take several people to eat a mushroom this size.
The largest puffball ever found was discovered in Slaithwaite, in the United Kingdom, in 2010 according to the London Free Press. It had a circumference of 66.5 inches.
Read more: www.dailymail.co.uk