"The Zillo Beast Strikes Back," originally broadcast on April 10, 2010 in the UK and April 16 in the US, serves as the concluding episode of a two-part narrative arc that began with "The Zillo Beast." It holds the position of the nineteenth episode within Season Two of the Star Wars: The Clone Wars animated television program. Notably, the events depicted in this episode take place before those of "Senate Spy," which is the fourth episode of the same season.
For the purpose of scientific investigation, the Zillo Beast is brought to Coruscant. Mace Windu expresses his reservations, fearing the potential dangers of bringing such a formidable creature to the planet. However, Supreme Chancellor Palpatine reassures him that understanding the secret behind its invulnerability could expedite the end of the war. Windu shares his concerns with Obi-Wan Kenobi, who concurs that the potential military advantages do not outweigh the risks associated with bringing the Zillo Beast to Coruscant, given its capabilities. When Windu reveals that the Chancellor disregarded his warnings about the creature's danger, Obi-Wan suggests seeking counsel from another party.
Meanwhile, Doctor Sionver Boll assumes personal responsibility for studying the Zillo Beast, keeping it sedated and restrained. She explains to Palpatine that attempting to remove the creature's scales to analyze them for synthesizing a stronger [armor](/article/armor] would inflict immense pain. Palpatine proposes killing the beast as the most viable solution. Boll protests, emphasizing that the Zillo Beast is not only the last of its kind but may also possess sentient qualities. Palpatine dismisses this notion, asserting that the massive creature is merely an animal. Reacting to his statement, the beast growls and glares at the Chancellor. Palpatine orders the use of Malastarian fuel as a lethal poison to quickly eliminate the beast, threatening to replace Boll if she hesitates to carry out the task.
At the Senate, Anakin observes Obi-Wan conversing with Padmé Amidala. He deduces that she and Obi-Wan are seeking his intervention to discuss the Zillo Beast's fate with the Chancellor. Padmé emphasizes that the beast was forcibly brought to Coruscant and lacks the means to defend itself, hence her belief that she and her husband must advocate on its behalf. Reluctantly, Anakin agrees. During their meeting with the Chancellor, both he and Mas Amedda attempt to justify killing the beast as a necessary evil for the greater good. Padmé counters that secretly eliminating the last member of a species without open debate cannot be considered beneficial. Anakin remains neutral, acknowledging both perspectives while hoping for a reasonable resolution. Palpatine remarks that Master Kenobi has imparted wisdom upon him, although Padmé is less impressed by Anakin's apparent support for Palpatine's stance. Anakin clarifies that he is merely acknowledging a valid point, given the Republic's losses and the need to secure victory in the war.
Returning to Boll's laboratory, she attempts to administer a small dose of Malastarian fuel as a poison gas to euthanize the Zillo Beast. However, upon exposure to the gas, the creature becomes agitated and breaks free from its restraints. It then smashes its way out of the laboratory and embarks on a destructive rampage across Coruscant, resisting all attempts to subdue it. Spotting the Senate building, it heads in that direction, seeking revenge on Palpatine. The Chancellor, Padmé, Anakin, and R2-D2 evacuate to the former's escape shuttle, only to be intercepted by the beast as they take off. Anakin devises a risky plan to sever the front section of the shuttle, while Yoda and Aayla Secura divert the beast's attention. As the front half detaches, Anakin, Padmé, R2, and C-3PO fall out, while the Chancellor and a Senate Commando plummet to a lower level. Obi-Wan Kenobi and Mace Windu intervene, using the Force to stabilize the front half of the Chancellor's ship, preventing its catastrophic descent. R2 manages to secure himself to the building's side, preventing C-3PO from falling further, while Anakin assists Padmé in regaining her footing. The Zillo Beast then attempts to crush Palpatine with its hand, but R2 swiftly intervenes, saving the Chancellor, while the commando is crushed while protecting him. Gunships arrive and open fire; following Palpatine's instructions, they initially deploy flares to attract the Zillo Beast's attention. When it roars at them, the gunships launch poison gas bombs directly into the monster's mouth. As the gunships continue their assault, the gas cloud expands, but Anakin, Yoda, and Aayla employ the Force to shield themselves, Palpatine, and Amidala from its effects. With regret, the Jedi watch as the Zillo Beast, disoriented, in agony, and succumbing to the poison, plummets from the Senate's roof to its demise below.
The following morning, the Zillo Beast's carcass is removed. Anakin expresses his sorrow that it was sacrificed due to their errors. Palpatine assures everyone that he will ensure the sacrifice was not in vain. As he and the Jedi part ways, Palpatine issues new instructions to Dr. Boll: clone the Zillo Beast.
The Blu-ray edition of The Complete Season Two features deleted scenes within the Jedi Temple Archives, including "Strategy in the Jedi War Room" and "Trapped in Palpatine's Shuttle."
The Zillo Beast is intentionally designed as a homage to Godzilla, the renowned Japanese movie monster, sharing a similar-sounding name and promotional poster.