A mouse is annoying the family of Mr. and Mrs. Evil J. Evil, the scientists, and Snagglepuss is offered food and lodging if he will get rid of the pest. The trouble is that the Evil's little boy has been experimenting with the mouse, and the furry rodent is now six feet tall!

Poor Major Minor is disgraced and kicked out of the Adventurer's Club because he has never captured Snagglepuss. The Major decides to use Snag's passion for acting against him, and he mounts a road show, which fools the mountain lion. Successful at last, the Major drives his captive directly to the Adventurer's Club stage, but Snagglepuss outwits him when he asks permission to do a farewell performance.