We have more than one page that can be referred to as Sleeper.
- If you want the film by Woody Allen, see Film/Sleeper.
- If you want the comic book Ed Brubaker about the sleeper agent with an alien artifact, go to Comicbook.Sleeper.
- If you want the trope dealing with actual sleeper agents, go to Deep Cover Agent.
- If you want the concept of works that slowly become unexpected successes, go to Sleeper Hit.
There's also a band, several other films and a tv series that go by that name. If you are looking for someone who has fallen asleep, you might want to read this.