Early 17th Century Combination warhammer and warpick/six shot gun.  

Has six barrels concealed on it for six shots.  The head contains five barrels, their muzzles concealed by a hinged cover forming the edge of the hammer. The topmost barrel is ignited by a matchlock fitted on one side of the head, its mechanism concealed by a brass plate cut out and engraved in the form of a lion. A sixth barrel, also hand-ignited, is concealed within the haft.

Part of the Royal Armouries Collection, on display at the Tower of London.