Codename: Kids Next Door is an American animated series that originally aired on Cartoon Network from 2002 to 2008. It aired on Boomerang from July 2, 2016 to March 5, 2017 as part of Cartoon Network Retro. The series returned to Boomerang's line-up when the block returned on January 2, 2018.
The series follows a group of kids who are spies that are each reffered to only as a "numbah", such as "Numbah One", the leader of the group. Together, the five kids form the Kids Next Door (or KND for short). In each episode, the KND fight their way against bad guys and traps in order to save the day.