A Metropolitan Police officer has been crawling the London Marathon in a gorilla costume since the race began on Sunday morning.
Tom Harrison, who goes by the name Mr Gorilla, is raising money for the Gorilla Organisation and has yet to complete the 26-mile race.
The 41-year-old Londoner started at 10.34am on Sunday. By lunchtime yesterday, he had reached Rotherhithe station - about 11 miles into the course.
He has slept at friends' houses in the evenings after completing around 10 to 12 hours and 4.5 miles per day and has swapped between crawling on hands and knees and up on hands and feet to save his blistered knees.
"I'm going good, I've just been having a gorilla power nap. Just been napping on some bark chippings under an old tree, which is the perfect gorilla nesting habitat really," joked Mr Harrison while he was on a break, which he has been having to take every 100 to 200 metres.
There's nothing more encouraging for them when they're out there risking their lives for those gorillas to know there are people like Tom back home pushing themselves to the limit to raise money and awareness.
"It's hard work today. All of my muscles are aching now so I've probably had a few more stops than previous days, but I'm still going forward so that's what matters.
"It's all about raising the profile of the Gorilla Organisation and raising money. I don't really matter that much, I'm just a conduit to the gorillas in Africa."
Asked what advice he would give to others who might try to crawl the marathon, which he said has not been done before, Mr Harrison said: "I'd probably advise anyone else doing it to get a bit more training in. We only did about four crawling sessions beforehand.
"I'd also recommend painkillers and just bloody-mindedness."
"Anyway I better get crawling. Couple more days to go I think, then I'll be tumble turning down the mile."
He expects to finish the race on Friday.
The Gorilla Organisation is dedicated to conserving gorillas in Rwanda, Uganda and DR Congo, and Mr Harrison's Just Giving page for his marathon effort has so far raised more than €1,759 for the charity.
In his costume, the policeman has taken part in a series of fundraisers for the cause, including the Great Gorilla Run, Tough Mudder and running the same marathon last year.
"He's just this incredible personality who seems to me to be absolutely fearless, but he loves the gorillas." said the charity's director, Jillian Miller. "I thought he was mad at first, but you know when Tom sets his heart to do something, he absolutely does it."
The charity said €2,346 could pay for a team of rangers in the Eastern Congo for three months.
"There's nothing more encouraging for them when they're out there risking their lives for those gorillas to know there are people like Tom back home pushing themselves to the limit to raise money and awareness," said the charity spokesman.