The Repel Cape is an item from Paper Mario: The Thousand-Year Door. These capes are sold at the Souvenir Shop in Glitzville and by the salesman in Rogueport. When used, Mario or his partner gains the Dodgy status effect. This means some enemy attacks will miss the hero for two turns.
Flurrie's Dodgy Fog attack has the same Dodgy status effect for up to four turns, making it a better choice than the Repel Cape if one wants to save money and can spare some FP.
Zess T. can cook it by mixing a Boo's Sheet and a Point Swap