Battle of Cato Neimoidia
The Battle of Cato Neimoidia, which can also be referred to as the capture of Cato Neimoidia, marked one of the last engagements of the Clone Wars. In this battle, Plo Koon, a Jedi General, commanded the 442nd Siege Battalion of the Grand Army of the Republic against the Confederacy of Independent Systems. The objective was to seize control of Cato Neimoidia, the Neimoidian Purse World and headquarters of the Trade Federation. The Galactic Republic successfully secured the planet during the war's final hours. However, while on a post-battle patrol mission over a bridge city, Koon met his death when his clone wingmen, acting under Supreme Chancellor Sheev Palpatine's orders, enacted Order 66.
Prelude

During the Clone Wars' concluding year, the Confederacy of Independent Systems launched an invasion on Cato Neimoidia, the Neimoidian Purse World that served as the homeworld of Separatist Council member Nute Gunray and the central base for the Trade Federation. Anakin Skywalker, a Jedi General, and Ahsoka Tano, a Commander, spearheaded the Grand Army of the Republic's 501st Legion in a counter-offensive against the Separatists. However, they were summoned back to Coruscant following the bombing of the Jedi Temple, which resulted in a Confederate victory and the planet's fall under Separatist control.
The battle

In the Clone Wars' last days, during the Outer Rim Sieges, the capture of Cato Neimoidia was deemed a strategically vital objective to bring the conflict to an end. The Jedi Council deployed Plo Koon, a Jedi Master, to Cato Neimoidia. His mission was to lead the 442nd Siege Battalion, a unit specialized in breaching enemy defenses, against the Trade Federation's stronghold.
The battle involved a number of aerial engagements fought both above the planet and within its atmosphere. These included Aggressive ReConnaissance-170 starfighters and at least one Clone Z-95 Headhunter under Koon's command. Davijaan, known as "Odd Ball", flew alongside Koon over Cato Neimoidia at one point. During the engagement, Koon led starfighters in attacks against three Separatist Providence-class Dreadnoughts and droid tri-fighters. Also, Clone Flight Squad Seven participated in the battle. Eventually, the Republic forces seized Cato Neimoidia in the final hours of the Clone Wars.
Aftermath

Shortly after the Republic's triumph, Koon was conducting a patrol flight near a bridge city. Unbeknownst to him, Captain Jag, the clone trooper pilot piloted the ARC-170 starfighter flying behind him. Supreme Chancellor Sheev Palpatine contacted Jag and issued the order to execute Order 66. Jag, without delay, reconfigured his fighter and opened fire on Koon. The Jedi Master's Delta-7 Aethersprite-class light interceptor sustained a direct hit and was destroyed in an explosion, resulting in his immediate death. The remaining wreckage of the fighter crashed into a structure within the bridge city.