Babyfier, A.K.A. Experiment 151, is an illegal genetic experiment created by Jumba Jookiba. He is designed to throw entire planets into chaos by turning the population into babies; the antidote consists of two teaspoons of applesauce, one cup of milk, three mashed bananas, and a dollop of 100% Kona coffee. If left uncured, any de-aged victim will have to grow up all over again. His one true place is at the dog pound, where he turns old dogs into adorable puppies, thus making them more appealing to potential adopters. He is voiced by Tara Strong.
He was activated by an ocean wave. Lilo uses him to get into a movie she can't watch because she is not old enough, but Stitch, Nani, Jumba and Pleakley eventually get turned into babies as well. Gantu also gets turned into a baby when Reuben releases 151 on him. In the end, the effects of 151 are reversed and everyone is turned back into adults except for Gantu.
Babyfier is a small light pink, oddly sheep-like experiment with a big head with a baby-like face, tiny purple insect-like wings, stubby legs, short stubby ears, plump cheeks, blue nose, a yellow pacifier in his mouth and a long baby rattle-shaped tail with dark pink stripes. He stands 11 inches tall and weighs 24.3 or 5-11 lbs.
Babyfier can sprinkle a pink powder from his rattle-like tail over the target, causing his victims to regress both physically and mentally into babies (or toddlers in the Stitch! anime). If not cured, said victims will have to grow up all over again.
A mixture of two teaspoons of applesauce, one cup of milk, three mashed bananas, and a dollop of 100% Kona coffee will revert Babyfier's victims to their original age. Alternatively, a special type of flower unique to Izayoi Island can be used as a substitute for the Kona coffee.
Babyfier made an appearance in Season 2 of the Stitch! anime along with Hammerface, Link, Spike, and Woody. It is revealed that Hämsterviel reverted these experiments to evil using a recording of Angel's song, thus enabling them to wreak havoc on the island. In another episode, Babyfier was reprogrammed by Hämsterviel to transform his victims into toddlers instead of babies (and appropriately renamed Toddler-fier). He left Stitch in charge of several schoolchildren whom he turned into toddlers, including Yuna herself.
- Even though Stitch was not born as a baby (being a genetic experiment), Babyfier still managed to turn him into an infant.
- Babyfier's pod color is white.
- Babyfier is described by the experiment computer screen as, "Experiment 151. Primary function: Infant maker. Change the victim into their infant form".
- Babyfier's tail appears in the online game Jumba's Lab.
- Babyfier bears some resemblance to Mew from Pokémon, even having the same designation number, 151.
- In the English dub of the Stitch! anime episode "Link-age", Reuben states that Babyfier's favorite type of sandwich is puréed carrots.