A Dragonite shaped cloud appears at the end of the episode.
Despite Bill claiming the Dragonite present is the last of its kind, several other Dragonite appear in later seasons. It has been speculated that Bill refers to this Dragonite as the last of its kind not because of its species, but because of its size. The Dragonite in this episode is much larger than Dragonite seen later in the series.
The fourth wall is broken in this episode when Ash answers the narrator's question as to what Pokemon he currently has.
The plot of this episode was likely based on the short story "The Fog Horn" by Ray Bradbury. In the story, a sea monster who is the only one left of its kind, hears a fog horn that sounds similar to its own voice and it is attracted to it.
A Mewtwo carving appears on Bill's door.