Slamwitch is a giant monster created by Gramma Stuffum from the Kids Next Door episode, "Operation: F.O.O.D.F.I.T.E.".
After Numbuhs 1-5 overpowered Stuffum and her infantry, Stuffum brings in her beast, Slamwitch, to deal with them and succeeded only to have a monster fight with a giant hamster named Joaquin. They fought equally at first until Stuffum used "candied lizards" to obscure the hamster's vision and allow Slamwitch tobland some good blows on him. As Slamwitch gloated in victory, Numbuhs 1-5 (who are still alive and undigested), stunned the giant sandwich from the inside, thus giving Joaquin a succesful chance to turn the tides on Slamwitch and eat him entirely.