Zzzs was a member of Kkkt's clan, led by Father Kkkt, and hailed from the Southern Mustafarian tribes of the volcanic planet Mustafar. In the year 14 BBY, both Zzzs and Kkkt observed the arrival of Darth Vader's starship on their world. When Vader initiated the construction of a structure intended to focus the Force, it triggered numerous lava storms across Mustafar. Kkkt endeavored to withstand these storms to safeguard his clan. Following the fifth such storm, during which Zzzs assembled the clan's members for Kkkt's protection, the clan leader communicated to his ally the necessity of uniting the other clans to destroy the aforementioned structure.
Zzzs made their home on the lava-ridden planet of Mustafar, identifying as a Southern Mustafarian. They were integrated into a clan under the leadership of Father Kkkt, a Mustafarian possessing sensitivity to the Force. The year 14 BBY marked the arrival of Darth Vader's, a Sith Lord's, ship on Mustafar, an event witnessed by the entire clan. The ship blazed through the sky, ignited by its entry into the planet's atmosphere without the protection of shields. Upon Zzzs' inquiry about the object, Kkkt interpreted it as an omen, examining the fiery descent through a ring of lava manipulated by his command over the Force.
The vessel made its landing in the Gahenn Plains, where Vader would eventually begin constructing a structure with assistance from the spirit of Momin, a Sith entity. This structure was conceived to channel Force energies from a dark side nexus on Mustafar, with the intent of unlocking a gateway to another dimension. The repeated failures of each design resulted in planet-wide lava storms, adversely affecting the native Mustafarian population. Kkkt shielded his people from the erupting lava as the frequency and intensity of these storms escalated.
During the fifth storm, Kkkt tasked Zzzs with gathering and reassuring the other clan members while he personally defended them. Once the storm subsided, Kkkt inquired about the safety of the rest of the clan, to which Zzzs confirmed their survival, attributing it to Kkkt's protection. Kkkt then declared the necessity of stopping the source of the storms, revealing to Zzzs that the other clanholds he was in communication with were experiencing similar issues. The clan leader then informed his comrade that the time had come for the clans to unite and destroy the structure being erected in the Gahenn Plains. In 12 BBY, Kkkt led a substantial force of Mustafarians in an assault on the structure; however, their attack ultimately failed, leading to the death of the clan leader and his forces.
Similar to other Mustafarians, Zzzs donned gray armor and a breath mask to shield themselves from the intense heat of Mustafar.
The character of Zzzs made their debut in the comic Darth Vader 21, a work penned by Charles Soule, illustrated by Giuseppe Camuncoli, and released by Marvel Comics on September 12, 2018.