|Episode(s)||5.16 Dark Side of the Moon|
Bones is a Golden Retriever Sam befriended when he was young. Sam ran away while Dean was looking after him in Flagstaff (John was on a hunt). He spent two weeks on his own, living on Funyuns and Mr. Pibb.
Sam and Dean are shot, die and end up in Heaven. There they visit memories from their past, including the time Sam ran away and spent time on his own, with Bones - a happy memory for Sam, but not for Dean who thought Sam was dead at the time.