The Swedish group were taking part in the Adventure Racing World Championship through the Amazon rain forest.
Mikael Lindnord fed the animal a meatball before the team carried on - but the scruffy creature followed them.
They tried to get rid of him, primarily for his own safety, but he refused to go so he became a fifth team member.
The group of four decided to name him Arthur and have now adopted him and flown him back toLindord said: 'I came to
See link for amazing pictures: