The story centers on Sylvester finding his way into a circus, where he not only tries to catch Tweety for his meal, but attempts to one-up a lion (an attraction billed as "King of the Cats").
A carefree Sylvester walks into the circus singing his theme "Meow!" where he visits the various animal exhibits. There, upon seeing the lion exhibit, the unimpressed puddy tat immediately expresses his displeasure over the large feline's billing. However, Sylvester is far more interested in Tweety ... and thus the chase begins.
Tweety runs into the big top, where the lion (now uncaged) is waiting to maul Sylvester for his earlier remarks. From this point forward, the lion serves as both an antagonist for Sylvester and a protector of Tweety.
Sylvester tries beating what he thinks is a fire hose to free Tweety, unknowing that the "hose" is an elephant's trunk. The elephant grabs Sylvester with his trunk and — after crushing his chest — throws the battered puss into the lion's cage, where the lion finishes the job.
Other run-ins with the lion, elephant and other animals — all ending with Sylvester getting the worst of things — involve him exploiting his abilities as a high diver (Tweety directs the elephant to "drink it all down" (referring to the water) before Sylvester lands), a fire eater (the lion makes Sylvester eat the fire) and a high-wire walker.
In the end, Sylvester finally gets rid of the lion ... only to unwittingly lock himself in a cage with even more lions (also the antagonists for Sylvester). Tweety immediately takes a hat and cane and becomes a carnival barker ("Huwwy! Huwwy! Huwwy! Step wight up for da gweatest show on Eawth! Fifty wions and one puddy tat!") A loud roar erupts, and with Sylvester presumably having met his fate, Tweety changes his spiel: "Step wight up! Fifty wions, count 'em, fifty wions!"