The image shows a wolf howling at an invisible moon – presumably a reference to the "wolf pack" moniker that the franchise's characters adopt in The Hangover.
Bradley Cooper, Zach Galifianakis and Ed Helms will all reprise their roles in the third instalment, while Mike Epps will return as Black Doug.
The Hangover 3 will reportedly see the gang return to Las Vegas, and it has been confirmed that this will be the last in the series.
Todd Phillips, who directed the first two films, will also return to helm the trilogy's conclusion.
The Hangover: Part III is currently in pre-production, and will open in cinemas on May 24, 2013.
Watch Cooper and Helms discussing The Hangover: Part II with Digital Spy below: