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Sand Blaster is a supporting antagonist of the 2020 Disney+ animated film Phineas and Ferb The Movie: Candace Against the Universe. He is an alien soldier who serves for the Super Super Big Doctor.
Taking Over Feebla-Oot
Along with many of the Big Doctor's troops, Sand Blaster was involved in her previous plot to take over Feebla-Oot from its previous rulers (the Cowards), all thanks to a giant spore plant named Mama whose spores can be used to bend the Cowards to the Big Doctor's will.
However, the Big Doctor learns that the spores are diminishing as Mama is unable to produce more with "Remarkalonium" (or carbon dioxide). Since only carbon dioxide is unavailable on Feebla-Oot as they can inhale and exhale oxygen, the Big Doctor sends out a pod to Earth to capture Candace Flynn-Fletcher and Vanessa Doofenshmirtz, as the latter holds enough carbon dioxide to feed Mama.
Following the detainment of Phineas, Ferb and the gang (along with Vanessa's father Heinz Doofenshmirtz) after their arrival to Feebla-Oot, the Big Doctor reveals her true plot to Candace while chaining her to a treadmill to produce more carbon dioxide for Mama. Upon learning from Candace that billions of people on Earth exhale carbon dioxide, she sets her next move to invade Earth and subjugate humanity. As the Big Doctor rounds up Sand Blaster and her troops, she assigns Toilet Flower to watch over Candace and force her to produce more carbon dioxide until the invasion starts.
As the Big Doctor and her troops finally made to Earth, Sand Blaster is seen helping his soldiers attacking Danville while he calls in Toilet Flower, who is watching the invasion from several monitors with ease. However, Phineas and the gang return to stop the invasion and save Candace, who then used a t-shirt cannon to defeat many of the soldiers. Upon confronting Candace, Sand Blaster gets surprised when Candace fires a t-shirt at him, making him blow up his upper half. This allows Candace to use Doof's Chicken-replace-inator to send the Big Doctor and Mama back to Feebla-Oot, where Mama gets squashed to death by an elephant creature while the Big Doctor gets arrested by the Cowards.
It is unknown what happened to Sand Blaster afterwards, but it's more likely that he will be arrested alongside his fellow soldiers and sent back to Feebla-Oot to serve time in prison alongside the Big Doctor for their crimes, as they are last seen hauled into a police van by several police officers.