Gyokko

Gyokko was a member of the Twelve Demon Moons, holding the position of Upper Moon Five.

Red Light District Arc
Having been summoned to a gathering of the Upper Moons, Gyokko greeted Akaza, asking him how he was after ninety years and lying about being worried over his colleague's well-being. The potted Demon also greeted Douma, exchanging small talk about the pot he had given his fellow Upper Moon as a gift. Shortly after this, Gyokko listened as Kibutsuji Muzan informed the group that Gyuutarou and berated them for their uselessness. The Upper Moon informed his leader that he had information that would get him closer to achieving his goals, only to have his head ripped off due to the information being unconfirmed. He was then ordered to head over with Hantengu once he corrected his mistake, leaving him bemused. The potted Demon was then approached by Douma, who asked him about the information he had and if he could tag along, and was shocked as Akaza destroyed Douma's head from behind.

He witnessed Kokushibou cutting off Akaza's hand, and asked the Biwa Demon to transport him and Hantengu to their destination.

Swordsmith Village Arc
At the swordsmiths' village, Gyokko devoured an unsuspecting villager and spat him right back out, stating that it wasn't edible. He then noted that destroying the swordsmiths' village would severely weaken the Demon Hunters.

Trivia
Pots: Gyokko is able to teleport into different pots to avoid attacks. Though he cannot do this if the pot is destroyed.

Summoning: He can also summon non sentient, fishlike demons from these jars; though it is not clear wether he makes them inside the jars, or if he summons them from different locations. These summons could be related to the demonic creatures in Muzan’s base.