In the fiction Gundam Universe, Anavel Gato was a member of the Principality of Zeon's elite palace guard unit. During the One-Year War, at the Battle of Solomon, Gato earned the nickname "Nightmare of Solomon" for his ruthlessness in combat. He was absorbed into Aiguille Delaz's fleet late in the war, and withdrew with Delaz and his supporters after Gihren Zabi's assassination at the hands of Kycilia Zabi, his sister. He returns to the earth in October of UC0083 to seize the RX-78GP02 Gundam Physalis, and later utilizes this Mobile Suit's nuclear weapon against the Earth Federation's Naval Review.

Anivel Gato is a skilled pilot and a man of few words. Throughout Operation Stardust he repeatedly clashes with the Federation pilot Kou Uraki. Gato was mortally wounded inside the captured colony cylinder as he reprogrammed the thrusters to enable the colony to fall on North America. At the conclusion of Operation Stardust, Anivel Gato ordered the remaining Zeon troops to charge for the Axis Advanced Fleet. Although they fought bravely, most of the Zeon pilots attempting to break through Federation lines were killed, including Anavel, who elected to kamikaze the AMA-X2 Neue Ziel into one of the Federation's Salamis class cruisers.

During Operation Stardust, Aneval Gato had command of his own fleet, which was centered around Gato's flagship, the Musai class cruiser Peer Gynt. His fleet was destroyed at the conclusion of the operation.