628 is a possibly sinister experiment that appeared in pod from in the Lilo and Stitch episode, "627".
He was created after Stitch defeated 627. Seen only in pod form at the end of "627" as Jumba locked it away in a vault, saying "So much for experiment 627. Perhaps I will have better luck next time". He has not appeared in the series since then.
- Due to the fact that Leroy was referred to as 628 in some "Leroy and Stitch" trailers, he could possibly be Leroy.