Mr. Wigglebottom

Mr. Wigglebottom is a cat that the Hales picked up from a pound to use as a distraction for Benjamin Ripley in Evil Spy School. After using the cat, Alexander wanted to keep it, but Cyrus was against it. Erica and Ben seemed to have mixed feelings about the cat. Mr. Wigglebottom was never shown or mentioned in any other books, however, Stuart Gibbs confirmed in a comment on his blog that the cat now resides safe and sound at Alexander's house.

Appearance
Ben describes him as, "A scraggly Calico with mismatched eyes," implying he has complete heterochromia, a condition in which one iris is a different color than the other.