Sinker

Sinker, A.K.A. Experiment 602, is an illegal genetic experiment created by Jumba Jookiba. He is designed to slice enemy sea vessels in half with his large dorsal fin. His one true place is at a Japanese restaurant, where he uses his sword-like fin to cut up fish fillets and vegetables for the chefs to make sushi.

Personality
Sinker is shown to be greatly offended by the mocking of his size compared to the rest of him. He is also incredibly territorial and will claim an entire body of water, sinking any sea vessel that sails in that area.

Lilo & Stitch: The Series
Experiment 602 was the 602nd genetic experiment created by Jumba with Hämsterviel's funding. He was designed to slice enemy sea vessels in two with his massive, razor dorsal fin. 602 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.

At an unknown point after this, Experiment 602 was activated.

When Keoni was practicing for a boat race, 602 sunk his boat while Lilo and Stitch were watching.

Later, when Lilo and Stitch attempted to capture 602, the latter proceeded to sink their boat as well. When Jumba and Pleakley tried to go rescue them, 602 sunk their raft also.

602, named Sinker, then proceeded to sink Gantu and Experiment 625 numerous times when they attempted to catch the former, and presumably sunk other boats.

Later, Lilo, Stitch, Jumba and Pleakley stowed away aboard a cruise ship, where Lilo went to seek out the captain about Sinker's rampage. However, the four got caught and thrown in the brig due to Stitch's horseplay. After they managed to break out, Jumba hatched a plan to capture Sinker.

While Stitch, wearing scuba gear (and defying his aquaphobia), dove underwater to find Sinker, the latter retreated to a cave until he eventually came out, revealing the diminutive size of his body. Sinker, however, wasn't amused when Stitch laughed at the former's puny size.

Sinker then escaped, but Stitch chased after him and was able to grab hold of his large dorsal fin. Sinker sunk a fishing boat, where two people were using a net to catch fish. He then attempted to sink the runaway cruise ship, but Stitch managed to capture Sinker in the ship's anchor and chain.

Shortly after, Sinker found his one true place at a sushi restaurant, cutting up fish fillets and vegetables.

In "Drowsy", Sinker's picture was seen in Lilo's experiment scrapbook.

In "Ploot", Lilo tried to convince Sinker to help her defeat Ploot, but he was unable to because he was really busy cutting up food for a large party while Hatha, the other chef who worked there, was sick.

Leroy & Stitch
In the film's opening, Sinker can be seen popping his head out of the water and waving hello to Lilo.

Later, the first 624 experiments, including Sinker, 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.

Sinker participated in the following battle between the experiments and the Leroys.

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 fail-safe.

Stitch! anime
Sinker made an appearance in the Stitch! anime where Hämsterviel used him along with Slushy to attack a cruise ship that Hämsterviel had lured Stitch onto. It is also revealed that Sinker has a blind spot on his dorsal fin, and he will become immobile if forced into a horizontal position because of his large fin.

Trivia

 * Sinker's fin has differences in size, although this could be a continuity error.
 * Sinker's pod color is blue.
 * Sinker is described by the experiment computer screen as, "Experiment 602 Primary function: Sinker of enemies' ships."
 * Sinker is one of the few experiments to not appear in the group photo at the end of Leroy & Stitch.