Gustav Munchausen (Occasionally, and erroneously, spelled 'Gustab'), is a character from The King of Fighters.
Gustav was introduced in the GBA spinoff game The King of Fighters EX2: Neo Blood, where he hosted said game's tournament. Lusting for supernatural powers, despite being a multimillionaire already, Gustav channels the spirit of Goenitz into Sinobu Amou, the game's boss character, for use as his puppet. After Sinobu is defeated by the player, Gustav disappears without any explanation.
Gustav is much more infamously known due to his inclusion as the final boss of the M.U.G.E.N-developed King of Fighters fangame The King of Fighters Memorial. Story-wise, Gustav hosts another King of Fighters tournament to get revenge on Kyo Kusanagi and Iori Yagami for foiling his plans in EX2, requesting the help of his close assistant Psyqhical. With his monetary powers, Gustav manages to create clones of many major boss characters from the King of Fighters series, including Rugal Bernstein, Krizalid, both versions of Zero, Igniz, and even Kyo and Iori themselves.
Gustav's appearance in Memorial is heavily based off of Oswald's sprite sheet, therefore giving him very overdramatic poses. In-game, he is absurdly overpowered; being able to make use of infinite priority normals and projectiles, and full screen special attacks.
Hei Meiling is an edit of him.