A mysterious, god-like entity known as a Collector, they were originally trapped inside the In Between Realm where he spent centuries awaiting his release. When assistance arrived in the form of Emperor Belos, The Collector helped the emperor with the Day of Unity in exchange for his freedom. Once the event proceeded as planned, Belos went back on his word and abandoned The Collector in his prison, only to be freed from it later by King. Upon his release, The Collector took over the Boiling Isles and turned it into their personal playground with King as his bound companion.
During his takeover, The Collector resided in the Archive House with King, together partaking in a game with the transformed citizens acting out the adventures of King's life. After Luz helps him understand his wrongdoings he helps protect the citizens during Belos' attack and helps fix the Boiling Isles, including reversing the puppet spell placed on the Boiling Isles citizens. They chooses to return to the stars for some soul searching but occasionally returns to visit his new friends.
The Collector uses both he/him and they/them pronouns.