Operation: P.I.A.N.O. / Operation: Z.O.O.

S1, E11: "OPERATION: P.I.A.N.O." When an overzealous NUMBUH FOUR disregards orders and injures himself during a mission to destroy kid torture devices, the other KIDS NEXT DOOR welcome his replacement, an extremely ambitious hamster. "OPERATION: Z.O.O." A demented children's zoo owner captures the KIDS NEXT DOOR for her kid exhibit and the KND's only chance to escape means cooperating with their sworn enemies, the DELIGHTFUL CHILDREN FROM DOWN THE LANE.