While Billy's Dad is underwear shopping, Billy wears his dad's lucky pants, and accidentely rips them with Grim's scythe. He calls Ed, Edd n Eddy, and they recommend Kids Next Door for charity. Numbah 1 disguises as Billy while Billy is taken back to the Deep Sea Lab. Mandy arrives at Billy's house and knows Numbah 1 is not Billy, and tortures him into revealing the truth. Meanwhile, the Delightful Children From Down the Lane and Billy accidentely fuse with the scythes power to create the Delightful Reaper. Mandy takes over the KND by fooling Numbah 363 and the rest of the KND, but Numbah 5 knows she's not Numabh 1, but is taken to the med lab. The Delightful Reaper assimilates nearly all of Endsville (including Numbah 2) and grows more powerful. Numbah 1 and Grim try to get the KND to see sense but are imprisoned. Numbah 5 escapes and finds Numbah 1 and Grim. Grim and Numbah 1 fuse with the Bone of Barnacles and become the Skeleton Samurai. Mandy in her Mandrobot (Monkeys And Nice Doggies Relax On Bellies Of Turtles) fight the Delightful Reaper, and so does the Skeleton Samurai, but they cannot defeat it. Grim finds out that the pants are Billy's Dads pants (which we now find out are immune to lasers, supernatural energies and mustard). Mandy is their only hope to defeat the Reaper, but instead they fuse with the Reaper. Billy's Dad takes off the pants, they destroy the Reaper, and all the kids return.
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