Skull Leader was the callsign of the leader of the Mandalorian starfighter squadron Skull Squadron. By the time of the Third Battle of Mygeeto around 19 BBY, Fenn Rau was Skull Leader, leading his Fang fighters against B1 battle droids to protect Jedi General Depa Billaba and her allies in the Southern Mesas.
Skull Leader was tasked with leading Skull Squadron, a squadron of Mandalorian Fang-class starfighters. When the Mandalorian Protector Fenn Rau held the title, he wore protector armor with blue markings.
By the time of the third battle of the Outer Rim planet Mygeeto, which took place around 19 BBY as part of the Clone Wars between the Galactic Republic and Confederacy of Independent Systems, Mandalorian Protector Fenn Rau served as Skull Leader. During the battle, he led his squadron against battle droids.
Fenn Rau flew his Fang-class fighter while serving as Skull Leader.
Over the course of two minutes, Rau and his squad wiped out a force of B1 battle droids in the Southern Mesas to save Jedi General Depa Billaba, Jedi Commander Caleb Dume, Clone Captain "Styles," and clone trooper Stance. Rau hoped their actions would showcase there were still Mandalorians with obligations and honor, departing with the rest of the squadron after their attack, so Dume was unable to thank the Skull Leader. At another point, Skull Leader Rau flew his Fang fighter through a volcanic environment. Later, Rau came to view his actions as only occurring because he had been young and idealistic, although Dume, having since changed his name to "Kanan Jarrus," finally met him in 3 BBY on the third moon of the Outer Rim planet Concord Dawn, recalling his actions during the Clone Wars.