Like Stitch, he is able to mutate into a second form with four arms, two long antennae, and three spikes on his back. However, his eyes glow bright purple when doing so, and energy radiates off his body. He possesses Stitch's abilities of enhanced strength, invulnerability and fighting skills. He also possesses other abilities, such as creating faults in the ground, flight, teleportation, purple energy blasts and electricity.
Delia began the creation of Dark End at the beginning of the third season of the Stitch! anime and continued working on him until the second-to-last episode. Delia then invaded Earth and sent out Dark End to defeat Stitch. Dark End easily had Stitch on the ropes even with the help of some of the other experiments. However, Stitch eventually defeated Dark End by using the power cell hidden inside of him he had. Afterwards, Jumba caught Dark End in a container, and the Grand Councilwoman arrested Delia, Hämsterviel, Gantu and Reuben. Dark End has not been seen since.