Lock, Shock, and Barrel attended a trick or treating school. Beneath their masks, they always are a devil, witch, and ghoul. Lock's the trio's leader, while Shock's the crafty, smart one, And Barrel is the dummy, whom they knock around for fun. "Trick or treat, smell their feet, give them something good to eat!"Here come the professional trick or treaters who carry out the mischievous deeds of the creepy Oogie Boogie. They're his li'l henchmen out looking for a fiendishly fun time! Lock, the leader, wears a devil's mask, Barrel wears a ghoul's mask and sly, smart Shock, is dressed as a witch. When they take their masks off , they're exactly the same underneath. Delighted by Jack's assignment to capture "Sandy Claws," they think up deliciously nasty ways to trap the "big red lobster man. Lock and Shock always practice their tricks on Barrel. He's their ghoulish guinea pig, and they use him to test out all the things they're planning to do to "Sandy Claws." Lock, Shock, and Barrel travel around in a walking bathtub. Usually, the scheming trio works for the villainous Oogie Boogie capturing bugs for him and then sending them down for his enjoyment, but after a whispered secret consultation they undertake a delicate mission for Jack Skellington-to kidnap Santa Claus. The three little demons are beside themselves with glee. Together, they fiendishly think of all the horrible ways they can trap "the big red lobster man." They are going to have lots of fun. The first time they enter the wrong holiday tree and kidnap the Easter Bunnt, but after returning him, they bring back Sandy Claws. Jack tells them to take care of him and make him comfortable, but they decide to send him down to Oogie Boogie and using plungers they stuff him down their pipe-line. After Oogie is destroyed they bring the rest of the town members to find Jack in Oogie's lair. Lock, Shock, and Barrel live in a tree house. Inside their is a pipe-line to OogieBoogie's domain. Inside they have a cupboard filled with deadly toys.