Garu Garu was the Monster of the Week on ep.15 of the UFO Robot Grendizer Anime and was the personal Mecha of Commander Yara. The Monster like many beast of the Army, was Disk Shape in its vehicle form, Blue and Grey in color, with Spikes protruding from the sides, with the added caveat it had its head coming out from the forward portion of the vehicle, almost similarly like Grendizer thus.

Its robot form is that of a Humanoid Warrior: Torso and Shoulders where dark orange, Grey abdomen and Brown Pelvis, with a orange color neck and head and Purple face with Black lining under the eyes, Yellow eyes and Orange rivets on the shin and had a Red Helmet. It's arms were Grey and Orange with Purple Joints. It had an orange right hand and a Bow that shoot arrows for a left hand. It's legs were grey, with Purple joints and feet. The Bottom part of the UFO shell becomes a defense shield that it could detached from the chest and carry, while the UFO's upper shell was attached to the back, with more arrows coming out from it. Outside from its Shield and Arrows, it could spin and burrow under the ground in its Saucer mode, like many other Beast do, fire a red laser and hoover in its robot. Garu Garu is the first Beast to actually have done some level of Physical Damage to the Spazer, by cutting one of the Spin Saucers off during its final fight.

The Episode introduces us to Commander Yara, a Vega Scientist who studies Geology and protested the weaponize use of its research by Vega. After been held in an underground Prison facility on the Dark Side of the moon, he is taken to Gandal and Blacki, who threaten him by having his elderly mother been sentence to the Flaming Ghost Planet.

Side Note: once a planet called Blue Paradise Planet, it was describe as a beautiful world with abundant resources which was among the first to be conquer by the Vega Empire and transform into a Industrial Mining facility for its war effort, using Prisoners from the fallen worlds as it Workforce. The disastrous environmental changes cause by the pollution from the factories changed the air and sea, making it hostile for it's denizens, thus acquiring its now more infamous name.

Realizing this would mean the death sentence to his mother, Yara capitulates to the villains demands and is sent to Earth on its Mecha to work on its Earthquake Machine to destroy the Kanto Region, although under the condition he'll capture Duke Fleed if it mean it would stop the use of the machine.

Not longer, various small Earthquakes begin to strike the area, Koji takes off on the TFO to investigate the source of the tremors been in the Kanto Mountains. As the TFO reaches the area, its detected by Yara, who launches Garu Garu and tries to capture Koji for bait, Daisuke launches Grendizer but when he arrives, Koji is taken down and Yara puts Garu's foot on the TFO, developing a hostage situation. After hearing Yara's request for Duke to surrender in exchange for Koji's life, promesing to not unleashing the power of the Earthquake Machine on the Region, and expressing his nature against killing, Duke accepts and Koji is let go in exchange. Duke surrenders land Grendizer and is detained. Both he and the Mecha are taken to the secret base, with Koji knowing the location, and retreating to formulate a rescue plan. Despite his success, Yara is inform by Blacki their plans to go forth in unleashing the full power of the Machine, as a Show Vega's Might by sinking the Kanto Region. Despite his protest and agreement, Blacki orders Yara to execute Duke by throwing him onto the lava pit, but after the transmission ends, concern of Yara, Blacki orders Capt. Bouchi (Yara's warden) to arrest him.

On the Observatory, Koji and Umon discuss ways to sneak into the base, and Koji comes with a solution inspired by Goro and Bunta, who are playing with Ski-Gliding. Back at the base, Yara has a private conversation with Duke in his cell and informs of the situation, and gives Duke the Computer Tape for the Earthquake Machine, without, the machine doesn't work. After leaving, Yara returns to his quarters where he writes a note to his mother when Capt. Bouchi arrives and arrest Yara taking him to the Motherburn for his act of resistance, Blacki informing him he was no longer needed to complete the machine. In one last bit of deception, Blacki informs Yara her mother had actually died on the Flaming Ghost Planet, making all of his efforts in vain, and sends Yara to the brain washing machine, where he is reprogram into a loyal servant. Yara flies back to the base, and Koji takes the chance to glide into the entrance, making it on time. Duke is then taken to the Lava Chamber for his execution, but Koji breaks in saves Duke, the two run back to the Mecha, board it and take off, with Yara following them in the Garu Garu.

After the beast breaks one the Spin Saucers, Duke launches Grendizer, where he faces Garu Garu. In the brief fight, Duke uses its remaining Spin Saucer to damage the robot, ripping a hole from behind through the abdomen, allowing him to cut the mecha vertically in half with Double Harken, though still remain functional. Blacki orders to unleash the power of the Earthquake Machine, but his goal to destroy the Kanto region is foiled by Yara's previous actions in surrendering the Computer Tape to Duke, before the Brainwashing. In his last act of Resistance, Yara breaks free from his control, fires one last arrow into the sky, shouting "I cannot kill!". Garu Garu falls down to the mountains and explodes on impact, killing Commander Yara, and causing an avalanche. Duke bids farewell to Yara, and as Grendizer flies away, Yara's last letter to his Mother is seen resting over the snow as the sole silent tribute to both of them.