After watching a horror movie based on a series of murders committed by a possessed dummy, a group of friends locate the actual dummy and they attempt to resurrect the spirit. The seance fails, but the dummy comes to life on its own.

《内裤队长》讲述了两个早熟的四年级小学生——乔治·比尔德（George Beard）和哈罗德·哈钦斯（Harold Hutchins）利用催眠术把他们的讨厌校长本尼·克鲁普（Benny Krupp）先生变成了穿着内裤的超人——“内裤队长”！这个内裤超人对孩子们很友善，总是能帮他们摆脱各种麻烦，但一旦恢复清醒，就会忘了自己作为“内裤队长”所做过的事情。