Singer Michael Bublé turned up on The X-Files in a flashback sequence on a U.S. Navy submarine in the episode Piper Maru from the third season (Piper Maru, the name of a ship in the episode, is actually the name of Gillian Anderson's daughter). Bublé played a navy officer, and it was long before he ever hit fame as a singer. In fact, it's the earliest credit on record for the mutli-time Grammy award winner, although he was uncredited when the episode (and it's follow-up, Apocrypha, in which he also appeared) first aired. Of course, the crew fall victim to a predictably terrible fate: trapped on board with them is an alien capable of using radiation to kill them all.