You're a Cat, I'm a Dried Tuna

Vivian wants to become a star so badly that she's even willing to become Lupin's victim if it'll make her famous, but a slip of the tongue causes her to say "Lupin stole a cat that eats pencil shavings." Lupin, infuriated at the grade-school newspaper report, begins a search for the cat in question, feeling disgraced at having been accused of stealing something so stupid. The duo of Bucky and Butcher also get mixed up in the proceedings. But does this cat really exist?