Yoko entdeckt auf dem Planeten Dehydropolis ein niedliches lebendes Fellknäuel. Sie schließt es in ihr Herz und nimmt es heimlich mit, obwohl Lehrer Spzoerscliipw den Schülern streng verboten hatte, irgendetwas auf dem Planeten zu berühren. An der Galaxy High angekommen, wäscht und shampooniert Yoko das kleine Wesen – mit ungeahnten Folgen. Durch den Kontakt mit Wasser vermehrt das Tier sich explosionsartig und mutiert in alles fressende kleine Monster...
When several Galaxy High teams are taken on a class field trip to an exotic planet, they are warned to only observe the environment and not to touch anything. Not heeding her teacher’s warning, Yoko spots a cute, tiny little alien creature and covertly confiscates it to take back to GH as her pet. Back at Galaxy High, Yoko goes to extreme lengths to keep the pet a secret from the faculty and other students. But one night, after giving the cute creature a bath, it begins to multiply like mad, budding into hundreds of nasty identical aliens. As the school becomes overrun by these creatures, Yoko has no choice but to come clean and admit what she did. In a b-story, Josh and Brett have to train Fluffy when the ultrapet begins misbehaving until it is soon discovered the ultrapet has the fleas.
