Experiment 275 was the 275th genetic experiment created by Jumba with Hämsterviel's funding. She was designed to tickle people into utter hysterics. 275 and the other first 624 experiments were deactivated and smuggled to Earth by Jumba during his mission to capture Experiment 626.
All the experiments were released and scattered across the island of Kauai.
At an unknown point after this, Experiment 275 was activated and captured by Gantu.
In "Snafu", Tickle-Tummy was freed along with Gantu's other captive experiments by Lilo, Stitch, and several other experiments in a rescue mission. She then tickled Reuben into hysterics, after he denied being ticklish.
The first 624 experiments, presumably including Tickle-Tummy, were rounded up by Leroy and taken to a stadium to be destroyed. However, Lilo, Stitch, Jumba, Pleakley, Reuben and Gantu arrived before the experiments could be destroyed.
It is unknown whether or not Tickle-Tummy participated in the following battle between the experiments and the Leroy clones.
The Leroys soon gained the upper hand in the battle but were defeated when Lilo, Stitch, Reuben and several other experiments performed the song "Aloha ʻOe", which caused the Leroy army to shut down due to the original Leroy's fail-safe.
- Tickle-Tummy is one of the rare experiments to not have black eyes like most experiments, having dark blue eyes instead.
- Tickle-Tummy was not on the list of the original 626 experiments in the end credits of Leroy & Stitch, but she is called 275 in Stitch!. 275 is the number Wormhole is listed as in the end credits. However, in the anime, Wormhole is called Experiment 272, which was originally the number of an experiment called Mamf. When asked about the numbering, Jess Winfield stated: "The best I can tell you about Tickletummy/Wormhole is that Jumba's genius does not extend to keeping a tidy database. There is some confusion in his records regarding Tickletummy, Wormhole, and a third experiment named Mamf, with different lists giving different numbers for them. Perhaps it will be sorted out someday."
- Tickle-Tummy is one of the few experiments to not appear in the group photo at the end of Leroy & Stitch.