Spike (Lilo & Stitch)

 Spike, A.K.A. Experiment 319, is an illegal genetic experiment created by Jumba Jookiba. He is designed to fire spines that make his victims goofy and stupid. His one true place is as a hugging therapist in Pleakley's E.A.R.W.A.X. group. Spike is voiced by Frank Welker.

Bio
Experiment 319 was the 319th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to fire spines like darts that cause any hit victim's goofiness to increase by 99%, leaving them only 1% clever.

319 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, with 319's pod landing by an outdoor stage.

Lilo & Stitch: The Series
When a water bottle was dropped, the water trickling out touched 319's pod, activating the experiment. 319 then spiked two nearby people and then the entire audience, causing them to act goofy.

Later, 319 attacked a museum and was captured by Stitch, but not before spiking him and Jumba. Fortunately, 319's goofiness-inducing spines didn't affect Jumba (since he was already a genius) as much as Stitch.

319 was then taken back to the Pelekai household and named Spike.

Spike was one of the experiments in Pleakley's E.A.R.W.A.X. group. When a sudden fight broke out between Slushy and Splodyhead, a stray fireball from Splodyhead destroyed Spike's container, freeing him.

Spike then went on a rampage, chasing Nosy around the house and then targeting Pleakley. Forced to resolve the situation, Pleakley donned protective armor against Spike's spines, and attempted hugging therapy on Spike, which surprisingly worked on the latter.

The following night, Pleakley took Spike with him, Lilo and Jumba to the Ohana-Rama. Spike then offered Lilo a hug to cheer her up when she felt down. Lilo declined, however, because although Spike was rehabilitated, she didn't want his goofiness-inducing spines to ruin her chances of competing.

During the contest, Lilo, Stitch and Spike soon discovered that Teresa was helping Mertle cheat, so Lilo convinced Spike to hug Teresa. Once Teresa got spiked, Mertle could not longer cheat. After Lilo won the Ohana-Rama, Mertle stormed out in anger. Spike felt sorry for Mertle and decided to hug her as well, spiking the latter.

Spike was later found a one true place in Pleakley's E.A.R.W.A.X. group, hugging and thus taming other truant experiments, while wearing protective armor to cover his goofiness-inducing spines.

Leroy & Stitch
The first 624 experiments, including Spike, 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.

Spike participated in the following battle between the experiments and the Leroy clones by firing goofiness-inducing spines at Leroys.

However, 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.

Stitch!
Spike made multiple appearances in the Stitch! anime including one instance with Hammerface, Babyfier, Link, and Woody. He was also used by Hämsterviel to try to sabotage a quiz competition. It is shown that he has the ability to roll into a ball and launch his spikes while spinning at incredibly high speeds.