Underfoot Cat is ingenious, but not always very plausible.

ME: Underfoot Cat, what have you done with my glasses?
UNDERFOOT CAT: What makes you think it was me?
ME: Well, there's only the three of us in the house, and it wasn't me and it wasn't Catzilla.
U.C.: How do you know there's only three of us in the house? You could have gremlins! Poltergeists! A secret cat!
ME: No, I couldn't. Besides which, you were sitting beside them on the counter just before they disappeared.
U.C.: That's nothing but circum . . . circumstitial . . .
ME: Circumstantial.
U.C.: I knew that. Circumstantial evidence. Doesn't prove a thing.
ME: And yet, here are my glasses, under the bathtub, and there are you, the only creature in the house who could have knocked them there.
U.C.: Um. I plead the Fifth?
ME: Even if you had Constitutional rights--which you don't--that wouldn't be one of them.
U.C.: All right! All right! I confess! I did it! I did it! I repent!
ME: . . . Your repentance looks an awful lot like rolling around on the floor and picking a fight with the bath mat. And losing.
U.C.: 'S not my fault if interpretive dance is the best of my limited options for communication.
ME: [giving up] Yes, let's both just pretend that's what that was. Try to remember that my glasses are not a toy.
U.C.: You say that about everything. [exits grumbling] It was all the Secret Cat's fault anyway.
ME: [after him] We don't have a secret cat!