The Protoplasmic Growth Ray is one Jumba's inventions constructed to make things big and small. It was seen in a couple episodes of Lilo & Stitch: The Series.
Background
In "Shortstuff", the ray was used to enlarge Stitch, who wanted to be bigger than his normal size after he was unable to participate in any carnival rides. However, due to interference from Experiment 297 (Shortstuff), the ray not only enlarged Stitch, but Shortstuff as well. Stitch was later shrunk back to his normal, functional size with Jumba's ray so he could defeat Shortstuff when the latter went on a rampage at the carnival. Meanwhile, Gantu somehow got a hold of Jumba's ray and used it to enlarge Reuben into a behemoth. He then commanded the gigantic Reuben to crush Lilo and her ʻohana. Instead of following Gantu's orders, Reuben plodded over to the enormous submarine sandwich that he noticed earlier and began devouring it hungrily while sitting on top of a humiliated Gantu.
In "Poxy", the ray was used to shrink Lilo and Stitch to microscopic size so they could travel inside Pleakley's body and extract Experiment 222 (Poxy), which was making Pleakley sick. The ray was also used to shrink Gantu when he tried to crush a delusional Pleakley for beating him up, although Gantu was reverted back to his normal size after Lilo planted Poxy inside him, making Gantu deathly ill as a result.
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