Thief Guild Master

From UOGuide

The Thief Guild Master is an NPC character found in random locations in most towns. He or she is ostensibly the Guild Master of the Thieves Guild, notably the only NPC Guild a player can join.

Players must seek out the thief guild master in order to join the Thieves Guild as well being at least 48 hours old and having a minimum of 60 Stealing skill. Upon joining the Thieves Guild, players may begin stealing from other players in Felucca. On the shards of Siege Perilous and Mugen, stealing is not restricted to the Felucca facet, according to the Siege Ruleset.

The thief guild master also sells the Disguise Kit, but only to characters who are already members of the Thieves Guild.