Numbuh 275, real name Jacob, is a KND scientist who appeared in Operation: F.E.R.A.L. He was based on a boy named Jacob whose wish through the Make-A-Wish Foundation was to appear in an episode of Codename: Kids Next Door. He also had a few cameos in several other episodes. His last appearance is Operation M.O.N.S.T.E.R. and he got eaten by a giant monster.