A dad fearing he'd been spiked was left horrified to discover he'd actually been bitten by a venomous false widow spider.
Nathan Green felt the moment the eight-legged predator sunk its fangs into the back of his right calf when he was out with pals.
But the 50-year-old didn’t think anything of it and brushed the irritant away, enjoying his afternoon at the pub on Sunday, June 12.
That night the tug company manager stumbled into bed shivering and feeling unwell.
The next day he woke up feeling “like he’d been run over” and began to fear he had been the victim of drink spiking.
A "small football-sized" blister bubbled up on his right calf and within 24 hours his leg ballooned to "three times" its size.
He then rushed to A&E on the orders of his wife, Dawn Green.
There doctors assessed his gruesome, swollen leg and revealed it was a reaction to a spider bite.
Stomach-churning photos show the huge yellow blisters that erupted across the dad-of-three’s leg.
Doctors were forced to pierce and drain them of pus leaving him with a foot-long patch of raw, agonising skin.
Three months on from his terrifying ordeal and Nathan’s leg still hasn’t fully healed, but he’s issued a desperate warning to Brits to be weary of false widow spiders.
Nathan, from Lowestoft, Suffolk, said: "You wouldn't think a little spider could do so much damage, it's unbelievable.
"I've been jumping around on boats and oil rigs all over the world and I've walked through jungles and swam in rivers, you name it I've done it, and I go to a pub and get bitten.
"Before [this happened], if my family saw a spider I would pick it up with my hand, open the window and throw them outside, they never worried me at all.
"But after getting whacked like this I'm cautious. If it has a skull on its back or looks like it may have a skull, they're getting it."
Nathan had been wearing jeans at the time of the bite and by the time he got home he had started feeling ill.
But it got drastically worse the next day.
"The next morning I woke up and I felt like I'd been run over, I couldn't go to work. I felt that bad, I thought that somebody had spiked me. I felt really, really ill," he said.
He added: "The wife said 'are you alright? You really don't look well'.
"On Tuesday morning I woke up and from my knee to my ankle was bright red, about three times the size it should be and it was rock solid.
"Then I noticed this blister on the back of my leg and within an hour it had doubled in size.
"By the time I got to A&E it had turned into a small football, every time I looked at it it got bigger. I'm bloody glad my wife made me go.”
Nathan went into anaphylactic shock, he said, and the blister had to be cut open and drained.
Once it was cleaned and dressed he was sent home, but the wound soaked through his new dressings so quickly they had to be replaced every six hours.
Nathan said: "It's up there with the worst pain I've ever felt, I wouldn't wish this on my worst enemy.
"Three weeks later I was still hobbling around like an old man. The hospital said If I'd left it later it would have caused more damage to my leg.
"My advice to anyone who gets bitten is to go and get it checked out. I'm a hardened 'I'll-work-until-I-drop' type of geezer and I'm glad my wife insisted I go to A&E."