Tarr Seirr, a male Cerean Jedi Knight, participated in the Clone Wars, fighting against the Separatist forces. Raised within the Jedi Order, he served as a Jedi Watchman for his home system, Cerea, offering counsel to the planet's governing body during the Separatist Crisis. With the onset of the Clone Wars, he was reassigned from Cerea to fight alongside Ki-Adi-Mundi, a Jedi Master he greatly admired. In 22 BBY, he was chosen for an elite squad tasked with the destruction of a droid factory belonging to the Confederacy of Independent Systems on the planet Hypori. However, the Republic fleet transporting the Jedi and their clone troopers was shot down before landing. Only Seirr and five other Jedi survived the crash, only to be immediately surrounded by a droid army commanded by General Grievous. After the surviving Jedi sought refuge inside a wrecked assault ship, Grievous ordered his droids to cease fire and engaged the Jedi in hand-to-hand combat himself. During the confrontation, Seirr attempted to attack Grievous from the rear, but the cyborg general seized him with a clawed foot, crushed him to death, and hurled his body, along with Aayla Secura, against the wall of the ruined ship.
Cerean male Tarr Seirr, born on Cerea and brought up by the Jedi Order, held great admiration for Ki-Adi-Mundi, a Cerean Jedi Master on the Jedi High Council who had been the Watchman for the Cerean Quadrant for many years. Having completed his Trials of Knighthood, Seirr was promoted to the rank of Jedi Knight. As the Separatist Crisis intensified, with Council members increasingly occupied, Mundi passed on his Watchman duties to Seirr. Shortly before the Clone Wars, when the Cerean government hesitated to formally align with the Galactic Republic, Seirr advised them to join in order to prevent the Confederacy of Independent Systems from seizing the planet. Ultimately, Cerea chose neutrality during the conflict.
As the Clone Wars commenced in 22 BBY, Jedi Watchmen were dispersed to various war zones, and Seirr was transferred from Cerea to a strategically important location. He was secretly unwilling to leave his homeworld, fearing a Separatist invasion, but he obeyed the order nonetheless.
As the Clone Wars continued, Seirr had the opportunity to fight alongside his idol, General Ki-Adi-Mundi. Around 22 BBY, Jedi General Daakman Barrek discovered a large CIS droid factory on Hypori. An elite squad consisting of Barrek and his Padawan, Sha'a Gi, along with Seirr, and Jedi Generals Ki-Adi-Mundi, Aayla Secura, Shaak Ti, and K'Kruhk, were sent to destroy the factory, backed by clone troopers from the Grand Army of the Republic. However, the mission was a disaster. As the Republic ships exited hyperspace, orbital mines of the Confederacy caused most of the transports to crash behind Separatist lines. Seirr and the other Jedi survived, but almost all the clone troopers were killed. The situation worsened when the survivors were surrounded by a massive droid army commanded by General Grievous, the Supreme Commander of the Droid Armies. In the ensuing battle, Seirr suffered a wound to his left arm, Barrek was killed by Grievous, and the remaining clone troopers were shot down by droid forces. Separated from other survivors and pursued by B2 super battle droids and OG-9 homing spider droids, Seirr and Ki-Adi-Mundi retreated into a crashed cruiser. Grievous, wanting to personally kill the Jedi, ordered the droid army to stop, while Seirr and Mundi ran inside the wrecked ship, where they reunited with the other Jedi. Moments later, Grievous told the survivors to prepare to meet a "warrior's death", and started to move toward the wreckage.
Inside the wrecked ship, the Jedi ignited their lightsabers, ready to confront the cyborg general. However, overcome by fear, Padawan Sha'a Gi broke down and fled the wreckage. Grievous swiftly crushed him, killing him, and hid inside the ship. The remaining Jedi retreated to the center of the cruiser, but were ambushed by Grievous, who leaped from the shadows. Despite being surrounded, the Jedi hunter held his own during the duel. Grievous soon gained the advantage, striking Seirr and the other Jedi away, severely wounding K'Kruhk, who lost consciousness. Shaak Ti then used telekinesis to hurl scrap metal at Grievous, while Seirr attempted to strike the general from behind. However, Grievous blocked the metal with his lightsabers, and after noticing Seirr, grabbed the Jedi Knight's head with his cybernetic foot, and crushed Seirr's head against the ground, killing him. He then threw the lifeless body of Seirr against the roof along with injured Aayla Secura.
Only Ki-Adi-Mundi and a severely wounded Shaak Ti, Secura, and K'Kruhk survived the engagement. Later, Seirr's fears were realized when unprotected Cerea became a battleground between Republic and Separatist forces vying for its allegiance. Consequently, much of the planet's peaceful wilderness was destroyed, and many Cereans were killed.
Tarr Seirr, raised within the Jedi Order, possessed a strong belief in the Jedi's cause. He adhered to the Jedi Code, even when it required him to leave something important behind; when assigned to a more tactical location away from Cerea, he suppressed his reluctance to leave the planet vulnerable and obeyed the assignment. He was deeply attached to Cerea and opposed its potential alliance with the Separatists.
Seirr greatly respected Jedi Master Ki-Adi-Mundi, and when Mundi relinquished his position as Watchman to Seirr, the young Cerean took the role with great seriousness, advising the Cerean government during the Separatist threat. During the Battle of Hypori, Seirr sought Mundi's advice during their retreat and stayed close to the Jedi Master even inside the shelter; when Mundi tried to stop Padawan Sha'a Gi for bolting, Seirr was the first Jedi who followed the Cerean Jedi Master. Seirr appeared nervous as General Grievous approached, but he did not hesitate to attack the cyborg later.
As a Jedi Knight, Seirr was a skilled swordsman, rivaling many Jedi Masters. Favoring Form 4, Ataru, Seirr proved to be an adept duelist, and because of this, as well as his Cerean heritage, he was selected to succeed Ki Adi Mundi as the Jedi Watchman of the Cerea System.
Despite the combined strength of him and the four Jedi generals, he was unable to defeat Grievous, who blocked and dodged their lightsaber strikes and ultimately killed him.
Tarr Seirr was a character created for Star Wars: Clone Wars, voiced by Daran Norris. In episode 20, he was credited only as Warrior #3. Much of his backstory was later detailed on the official Star Wars Databank. He also appeared in the mobile strategy game Star Wars: Battle for the Republic.