Mrs. Sickly, A.K.A. Experiment 255, is an illegal genetic experiment created by Jumba Jookiba and a character in the Lilo & Stitch franchise. She is designed to make people sick with her nauseatingly sweet fumes. She appears in Stitch!.
Experiment 255 was the 255th genetic experiment created by Jumba with Hämsterviel's funding. She was designed to make anyone sick with her nauseatingly sweet fumes. 255 and the other first 624 experiments were deactivated and smuggled to Earth by Jumba during his mission to capture Experiment 626.
All of the experiment pods were released and scattered across the island of Kauai.
Mrs. Sickly first appeared when Hämsterviel released her along with Mr. Stenchy during Christmas in Japan. As part of his plot, Hämsterviel mass produced clones of Mr. Stenchy and Mrs. Sickly and sold them to many children across Japan and the rest of the world. This is when it is revealed that if the emissions from these two mix, they have the power to destroy entire planets. This leads to Yuna, Pleakley, Stitch, Jumba, Hämsterviel, and Gantu on a hunt to round up the clones of Mr. Stenchy and Mrs. Sickly in order to save the world's Christmas.
Mrs. Sickly is a light blue Mr. Stenchy-like experiment with golden eyes, puffier antennae and smaller hair.
Like Mr. Stenchy, Mrs. Sickly appears disarmingly cute to everyone else except other experiments, but then emits an extremely foul and noxious odor 48 hours after she is activated. Additionally, if Mrs. Sickly's emissions intermix with Mr. Stenchy's sour emissions, the chemical reaction will cause a cataclysmic explosion capable of destroying the planetary body they inhabit.
- Mrs. Sickly is one of the rare experiments to have sclerae and pupils instead of solid black eyes, the others being Mr. Stenchy, Skip, Clink, Nosox, and Bragg.
- While it is confirmed that Mrs. Sickly is Mr. Stenchy's wife, it remains unconfirmed whether her one true place is on Plorgonar with her husband.