1 / 20
moment a sloth gatecrashed a groups holiday snap in the jungle. The group of youngsters on an International Student Volunteers expedition from all over the world had been helping cut paths in the dense woodland on Costa Rica to allow researchers to get around. And after completing their back-breaking charity work, they decided to have a group picture taken as a keep sake. But what they didn't expect was this inquisitive sloth slowly lowering himself down into the frame as the group smiled for the camera. Manuel Ramirez, who is an anthropologist and tour guide for International student volunteers , had decided to take the snap, but he was not aware that a fame hungry sloth was waiting above (Caters)

Best Animal Pictures Of 2012

From a cheeky sloth gatecrashing a holiday snap to a harmless gannet that transformed itself into a Great White, here is a collection of the most memorable animal pictures of the year.