As the droid army leader in the Clone Wars, General Grievous inspired fear throughout the Republc. Trained in lightsaber combat by Count Dooku, he travelled the galaxy, invading worlds and engaging Jedi. The metal-meets-organic monstrosity fought Ahsoka Tano and Obi-Wan Kenobi numerous times, always managing to escape.

Grievous maintained his own lair in a Separatist headquarters. Located on the third moon of Vassek, it contained several rooms and chambers, featuring statues of an alien warrior and multiple armors. The lair was discovered by investigating Jedi and clones, who surprised the General and demanded his surrender. While he suffered severe injuries, Grievous escaped and was restored by his doctor, A-4D; he regrouped to unleash a surprise of his own on the Jedi: Gor, his vicious pet roggwart. While Gor was destroyed, Grievous himself killed a young Padawan called Nahdar and overwhelmed Kit Fisto in lightsaber combat. The General survived to fight another day.

Under the orders of Count Dooku and Darth Sidious, General Grievous led a daring kidnapping of Chancellor Palpatine in the Battle of Coruscant. Keeping his prisoner in the custody of Dooku aboard his flagship, Grievous was unsurprised when Jedi Obi-Wan Kenobi and Anakin Skywalker arrived to stage a rescue. The Jedi proved victorious, with Anakin killing Dooku and freeing the Chancellor, but were soon apprehended by Grievous’ droids. Brought before him, Grievous took their lightsabers, boasting that they would make a fine addition to his collection. Thanks to some of R2-D2’s clever trickery, however, the Jedi regained their weapons and cornered the droid army leader. In a last-second cowardly move, Grievous shattered the bridge viewport and escaped into space.

Grievous headed for a major Separatist base on Utapau. Speaking with Darth Sidious, he was assured that the war was coming to an end, and the Separatists would be victorious. Still, it would prove to be short-lived comfort for the walking terror. Obi-Wan soon arrived with a battalion of clones, and the Battle of Utapau began. The General and Obi-Wan dueled, and despite wielding four lightsabers at once, Grievous was dismembered and once again tried to flee. Obi-Wan gave chase, and the two eventually fought in a knock-down drag-out fist fight. The Jedi had lost his lightsaber and found himself dangling from a cliff, and Grievous appeared to have the upper hand. As the General menacingly lurched forward, prepared to deliver the final blow, Obi-Wan used the Force to draw Grievous' blaster into his hand. He shot Grievous in the chest, igniting what remained of his organic matter, and the fearsome menace was no more.