Wondrous Item, rare (requires attunement by a Requires the holder to be called "worlds best _______". The mug then says on the outside whatever the creature was called.)
The Mug of Greatness isn't found by someone, but rather, it finds someone. Whether it be by coincidence, or a last minute birthday gift.
If the Mug of greatness is drank from the drinkers maximum for all stats is increased by one and gains +1 to all stats for an hour and feels slightly better about themselves.
Notes: Requires the holder to be called "worlds best _______". The mug then says on the outside whatever the creature was called.