Originally, Sokka hunted and attempted to kill Foo Foo Cuddlypoops for food, but when he jumped down to stab the animal, Foo Foo Cuddlypoops sidestepped the attack, leaving the Water Tribe boy to sink into a crack in the earth. The cub had a natural curiosity toward Sokka, who tried again to capture it. This second sudden movement caused him to sink even further into the fissure to the point where he could barely move. Sokka continually tried to escape the crack unsuccessfully, during which time Foo Foo Cuddlypoops wandered around him, slept on his head, played with his warrior's wolf tail, and even gave him an apple just out of his reach.
Sokka talked to Foo Foo Cuddlypoops as if the latter understood him, much like the way he spoke to Momo. The teenager, in frustration, soon hollered to "the universe" that, if he were to escape the hole in the ground alive, he would give up meat and sarcasm, noting that the pair were "pretty much his whole identity."
Hours later, when Aang found Sokka lodged in the crack, Foo Foo strutted toward him, and the Water Tribe warrior introduced the fluffy creature to Aang as his friend, for the first time calling him "Foo Foo Cuddlypoops". Aang immediately recognized the animal as a baby saber-tooth moose lion, much to Sokka's surprise. Following this revelation, Foo Foo's mother stormed in to witness that Aang was holding her baby. Aang quickly released Foo Foo, who ran happily toward his mother.
The mother then charged at Aang, who had no other choice but to stand his ground due to Sokka's entrapment in the fissure beside him. He eventually managed to drive the mother away by facing her head on and blowing her back with his airbending. In the end, Foo Foo Cuddlypoops left with his mother.