A Swedish extreme adventure team racing through Ecuador's Amazon rainforest ran into an unexpected companion: a stray dog who followed Team Peak Performance through the final two days of a 10-day, 430-mile course of extreme pain and extreme suffering.

They fed him a meatball and sent him on his way, but he didn't want to leave. He stayed with them through mud and mountains, until they ran into a 36-mile water stage. Because race organizers feared for the dog's safety, the team left him on shore while they took off in their kayaks.

But in the end, there was nothing they could do to stop the tough mutt from finishing the Adventure Racing World Championship. When the team realized he was swimming alongside them, they pulled him up into a boat and wrapped him in a jacket.

They named him "Arthur"—Swedish for "extreme," probably—and took him back home with them (after having him checked by a vet and winning approval from the Swedish board of agriculture). He arrived to a crowd of reporters and immediately held an extreme doggie press conference.

Arthur had a wound on his back when he was found, but it's said to be healing fast now. Of course it is. This dog is a badass.

Peak Performance came in 12th in the race, but they got a pretty good consolation prize.

"I came to Ecuador to win the World Championship. Instead, I got a new friend," team captain Mikael Lindnord said.

[h/t BBC, Photos: Team Peak Performance/Facebook]