在一个遥远的星球上,拥有先进文明的外星人发明了一种处理垃圾的特别方式:把垃圾转换成光源能量传播到外层空间。然而在一次传播途中发生了错误,被遗弃的外星怪物意外地被地球上普特曼一家用天线接收,从此他们一家将不再太平。A civilization on a distant planet has found a way to solve its garbage problem: turning it into energy and beaming it into outer space. A flaw in this system is found when the signal is accidentally picked up on Earth by the Putterman Family's home satellite dish. While this would ordinarily be just another mess, this particular transmission contains a hungry trash monster who quickly begins snacking on the Puttermans and their guests. Only young Sherman Putterman has any clue what is going on, but nobody will believe him. Is there any hope for the Earth?