Douglas, also known as Black Doug, is a minor character in The Hangover. He is portrayed by Mike Epps and is a friendly, laid-back, drug dealer who sold Alan roofies and was told it was ecstasy. He gets kidnapped by Mr. Chow because he thought he was hanging out with the Wolfpack at the Bellagio.
He returns in The Hangover Part III, this time as a villain having teamed up with his boss, Marshall (the main antagonist who was first mentioned in the original movie) and Doug is his Head of Security. Black Doug was shot and killed by Marshall because of his incompetence since Chow robbed Marshall's mexician villa, his death caused Alan to wet himself and he was also shown in a flashback from the first movie when Doug sold Alan the roofies.
In his appearance in the third film, when Black Doug and his gang first kidnapped the Wolfpack, his appearance somewhat resembled his portrayer Epps' character L.J. from the action-horror film Resident Evil: Extinction (as both characters wore a brown leather jacket, carry a variant of a Desert Eagle as their personal sidearm, get shot and killed by their own allies and appear in both films set mostly in Las Vegas which is also a third film in a film series).