Thresher

 Thresher, A.K.A. Experiment 544, is an illegal genetic experiment created by Jumba Jookiba. He is designed to smash up crops with his mace-like tentacles. He was captured by Gantu, but was rescued in "Snafu." His one true place is working with the local sugar cane farmers, using his tentacles to chop the stalks. Thresher is voiced by Tom Kenny.

Bio
Experiment 544 was the 544th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to smash up crops with his mace-like tentacles.

544 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.

Lilo & Stitch: The Series
544's pod eventually made its way to a junk shop, where it, along with 609, 617 and 033, was stolen by Gantu, activated, and named Thresher in "Dupe."

Plasmoid, Heat, Thresher and Hammerface were then led by Gantu in an attack on the Pelekais' house, where Thresher and the other three experiments were able to easily defeat and capture Stitch and his replicas.

The five returned to Gantu's ship for a victory feast, but were interrupted by Lilo, Pleakley and Dupe. Gantu used Dupe to clone Thresher into a hundred replicas, but as Thresher's power was thus divided between them, they were complete weaklings.

It is presumed that Hämsterviel was somehow able to re-merge the weakling Threshers into one.

Thresher reappeared in "Snafu," and was freed along with Gantu's other captive experiments by Lilo, Stitch, and several other experiments in a rescue mission.

Leroy & Stitch
The first 624 experiments, including Thresher, were round 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.

Thresher participated in the following battle between the experiments and the Leroy clones. When Stitch points to the stage in the stadium, Thresher can be seen bonking a Leroy clone on the head.

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 `Oe, which caused the Leroy army to shut down due to the original Leroy's failsafe. Thresher joins them for the song by playing the marimba.

Stitch! anime
Thresher appeared in the Stitch! anime where Hämsterviel used him to attack Stitch during a magic show. In this episode, he looks more muscular and has bright, orange eyes.