Mazzi was a colonel in the Nimbus commandos of the Nationalist Army during the Clone Wars; he was a male Human.
Mazzi, holding the rank of colonel within the Nationalist Army, collaborated with many officers of the Jabiimi Nationalists and led multiple Nimbus commandos throughout the Battle of Jabiim. His adversaries in this battle were the Grand Army of the Republic and the Jabiimi Loyalists. He operated directly under the leadership of Alto Stratus, typically remaining close to him. Following Alto's death at the hands of a Jedi, Mazzi, as the highest-ranking commando present, united the surviving Nimbus commandos and continued the fight against the Loyalists after the Republic's withdrawal from the planet.
Following the conclusion of the Clone Wars and the subsequent establishment of the first Galactic Empire by Supreme Chancellor Palpatine, Mazzi and the Jabiimi Nationalists formed an alliance with the new government. This alliance granted them the freedom to act against the rebellious loyalists as they saw fit.