Clone assassins, a unique type of clone trooper, were engineered by the Kaminoan cloning experts on the planet of Kamino. Supreme Chancellor Palpatine himself, through a clandestine order during the Clone Wars, commissioned these specialized troopers. Their training focused on eliminating Jedi using Teräs Käsi, a form of unarmed combat. They possessed exceptional speed, a knack for predicting attacks, and resistance to Jedi mind tricks.
Following the execution of Order 66, which compelled all clone troops to kill their Jedi officers, these assassins were fully deployed. Palpatine dispatched a unit of these clones to aid in an assault targeting the Jedi Temple on Coruscant, a planet, during 19 BBY. Leading the attack was Darth Vader, who, along with the 501st Legion, purged the Temple of Jedi. Inside the Jedi Temple communication center, Vader activated a beacon to contact all Jedi across the galaxy, ordering their return to the Temple. A large garrison of clone troops awaited them there, ready to kill them. When Jedi Master Obi-Wan Kenobi attempted to alter the message to warn away surviving Jedi, the squad guarding the beacon attacked, but he defeated them.
The Galactic Senate approved the creation of clone assassins for the Grand Army of the Republic at the behest of Supreme Chancellor Palpatine, secretly the Sith Lord Darth Sidious. Palpatine justified these troops by claiming they were needed to counter any potential Jedi rebellion against the Senate and the Republic.
In 19 BBY, the final year of the Clone Wars, Jedi Knight Anakin Skywalker, a close associate of the Chancellor, pledged allegiance to Sidious' Sith teachings and became his Sith apprentice, adopting the name Darth Vader. Subsequently, the Dark Lord dispatched a unit of clone assassins, along with Vader and the 501st Legion, to the Jedi Temple on Coruscant to exterminate the Jedi inside. During the Temple assault, Vader assigned a six-assassin squad to protect the Jedi Temple communication center. He had activated a beacon there, broadcasting a message to all Jedi in the galaxy falsely claiming the war's end and ordering their return to the Temple. A large clone troop garrison remained to intercept and eliminate any returning Jedi.
After receiving the beacon's message and learning of the Jedi Temple attack, Jedi Master Obi-Wan Kenobi and Grand Master Yoda, suspecting a trap, decided to infiltrate the Temple to halt the broadcast. Kenobi entered the Communication Room, where Vader's assassin squad ambushed him, but he successfully overcame them all.
To ensure their protection in combat, clone assassins received a standard variant of the Phase II clone trooper armor. Despite wearing this full-body armor, they could still execute incredibly agile movements to evade attacks without any hindrance. The armor incorporated two vibro-blades attached to the elbows, extending their reach and enhancing their offensive capabilities. These blades could be deployed from a concealed position and locked to align with either the troopers' upper or lower arms during attacks. The assassins wore split kamas, secured by a belt featuring two storage pouches on each hip. They also carried blaster pistols.
The sole purpose for the commissioning and creation of assassins was to fight Jedi on even footing. They received training in Teräs Käsi, a unarmed combat style developed specifically to defeat Jedi, combined with the use of twin vibro-blades on their arms. They could easily evade or deflect most strikes from melee weapons, such as lightsabers, and were resistant to Jedi mind tricks. While a squad of clone assassins could readily defeat a Jedi Knight, they were not a match for a Jedi Master. In addition to their unarmed combat skills, the assassins were proficient with blaster technology and carried blaster pistols. They assisted in purging the Jedi Temple and later defended the temple beacon room from Jedi.
This clone trooper type debuted as an enemy character in the video game adaptation of Star Wars: Episode III Revenge of the Sith. A bonus level features Yoda confronting several clone troop squads in the Temple, including a six-assassin squad, although the canonicity of this encounter is uncertain. Concept art for the game depicts a clone assassin with dark armor, contrasting with the white and blue armor seen in the game.
Raphael Sbarge, who also voiced Carth Onasi in Knights of the Old Republic and RC-1262 Scorch in Republic Commando, provides the voice for the assassins.
In the second Jedi Temple level of Obi-Wan's storyline in the GBA/DS versions of the game adaptation, Obi-Wan encounters a clone trooper with similar colors to the Clone Assassin. However, his attack style resembled that of the Heavy Weapons Specialist, using a launcher to fire grenades into the air to trap Obi-Wan.