Discovered by Shi'ar Emperor D'Ken. However, before D'Ken had a chance to study it, he died. ZZZXX has been classified as one of the five most dangerous criminals the Shi'ar Empire has ever captured and has been selected by Vulcan to serve in his new Imperial Guard.
During a fight with the Starjammers, ZZZXX took over the body of Raza Longknife. Unlike other symbiotes, ZZZXX didn't bother to ask permission or care to know his host, and for Raza, it was a harrowing experience being controlled.
Raza used medi-bots to separate the symbiote from himself. ZZZXX is currently being contained aboard the Starjammer. ZZZXX was thrown into the Fault, a massive rip in space-time that connects to a cancerous universe. Raza and Ch'od threw ZZZXX into a massive creature of that universe that was a putrid alternate of Professor X. It is yet to been seen how or if they react to each other.
It appears similar in appearance to Lasher, Venom, Agony, Scream and Carnage except it is black in color. All of its physical characteristics are variable, such as height, weight, etc.
Like all other known Symbiotes, he's weak to fire and super-sonic sound waves.