In the Star Wars: The Clone Wars animated series, "The Zillo Beast" marks the eighteenth installment of Season Two, initiating a narrative told across two episodes. It was initially broadcast on April 3, 2010 for UK viewers and subsequently on April 9 of the same year in the United States.
Mace Windu, Palpatine (communicating via hologram), and Anakin Skywalker deliberate over the potential consequences of deploying the Electro-Proton Bomb, the Republic's newest superweapon, on Malastare to secure fuel. They express concern that the bomb's effects might impact their own forces, alongside the droid army. Dr. Sionver Boll, the bomb's creator, assures them that it poses no threat to Republic personnel or the people of Doge Urus' nation, as it is specifically designed to target droids, with all possible outcomes accounted for. Despite Windu's reservations about unforeseen possibilities and his desire for an alternative solution, Palpatine insists that the bomb represents the Republic's best hope for victory.
Windu and Anakin observe the Republic and Malastare forces, outnumbered, advancing towards the Separatist army. On the Separatist side, the tactical droid commands an immediate attack. Captain Rex, clone troopers, Dug soldiers, and Cavaliers riding insectomorphs struggle to maintain their position under heavy fire, while Hyena bombers provide aerial support.
Eventually, the Republic authorizes the deployment of the electro-proton bomb against the overwhelming Separatist forces. The pilot releases the bomb, resulting in a massive explosion that obliterates the Separatist army. The explosion generates an EMP, disrupting Palpatine's transmission, disabling the clone tanks, and causing Anakin's prosthetic arm to malfunction. However, the clone forces and Dug soldiers remain unaffected.
As the troops celebrate their triumph, the ground begins to crumble and collapse beneath them. Rex leads the clones and Dugs in a hasty retreat to safety. However, some clones plummet into the sinkhole, prompting Anakin to organize rescue missions to locate the trapped soldiers. After communication with the rescuers is lost, Mace Windu and Commander Ponds decide to investigate and search for the missing troops, while Anakin finalizes the Treaty to authorize fuel purchase from Malastare. Dug leader, Doge Nahka Urus, expresses joy for their alliance while they wait for the rest of the council to arrive and ratify the treaty.
Subsequently, within the sinkhole, Windu discovers handprints and a clone helmet. The clones then locate the rescue team and some of the fallen troops; a traumatized survivor speaks of a presence lurking in the chasm. Windu, Ponds, and troopers Hawkeye and Trapper initiate a broader search. Windu requests Anakin's assistance, prompting Anakin to prepare his fighter and depart. As they approach a ledge, Windu and the troopers feel the ground tremble as the massive head of a huge reptilian creature emerges and roars at them. The clones' blaster fire proves ineffective against the beast. It dislodges them and pursues them until Anakin diverts its attention by flying in circles, enabling Windu and the clones to escape.
Anakin, taken by surprise, is caught off guard when the beast strikes his fighter, causing him to crash. He ejects just in time. Engaging the monster with his lightsaber, he discovers that its armor-like scales are impervious to the weapon. He jumps onto the beast's head and identifies gaps in its armor where a precise shot could penetrate, before leaping onto R2-D2 and escaping the pit. Following his dramatic exit, Urus arrives and identifies the creature as a Zillo Beast, the dominant species on Malastare before his people expanded across the planet, and predators of the early Dugs. Urus explains that the Zillo Beasts began to die out as his people began harvesting fuel. They were thought to be extinct... until now. The Dugs launch a futile bombing campaign against the Zillo Beast, while Mace and Anakin locate Urus and the council observing ancient texts detailing the Zillo Beast's weaknesses.
Windu and Skywalker argue that continuing their actions would lead to the extinction of an innocent life form, but Urus threatens to nullify the treaty if they attempt to protect it. A discussion with Palpatine reveals his support for the Zillo Beast's extermination. However, Dr. Sionver Boll and Anakin advocate for its preservation, suggesting that its seemingly impenetrable armor could be replicated for military applications. They propose stunning the creature by targeting the gaps in its armor with Stun Tanks. Once fully stunned and weakened, it would appear dead, but remain alive in stasis. The Dugs would then assume its demise and sign the treaty, allowing the Republic to relocate it to a secure facility for study and potential armor replication.
The Stun Tanks are deployed to the pit, much to Urus's satisfaction, who believes his plan is already succeeding. He instructs the Dugs to pump fuel into the pit, claiming it is lethal to the Zillo Beast and will kill it. However, Windu warns that such action will only enrage the Beast further. Windu implores Urus to stop, threatening to kill him if he persists, but the Dug remains defiant, asserting his own right to life. Windu's warning proves accurate when the provoked Zillo Beast emerges from the hole and wreaks havoc, destroying everything in its path. It climbs out and the Stun Tanks open fire, seemingly without effect. It swipes and destroys several tanks, causing Anakin to order backing up to avoid it. After a rampage, concentrated fire from the tanks start to weaken the Zillo Beast, and it eventually collapses, incapacitated. Sent into a deep coma by the cannons, the beast appears to be dead.
Urus signs the treaty, and Malastare becomes part of the Republic. Palpatine orders the Zillo Beast to be transported to Coruscant for study, a decision that concerns Windu. The episode concludes with four LAAT/cs transporting the Zillo Beast to Coruscant for research.
During a brief exchange between Mace and Ponds as they unknowingly walk on the Zillo Beast's back, the border of Ponds' kama appears blue instead of maroon.
In the initial scene where Palpatine receives a briefing on the Zillo Beast, Rex's kama is absent.
