Efreeti Bottle

From Dungeon Master's Guide, page 167. Found on Magic Item Table H.

Description
''Wondrous item, very rare. 1 lbs.''

This painted brass bottle weighs 1 pound. When you use an action to remove the stopper, a cloud of thick smoke flows out of the bottle. At the end of your turn, the smoke disappears with a flash of harmless fire, and an efreeti appears in an unoccupied space within 30 feet of you.

The first time the bottle is opened, the DM rolls to determine what happens.