I forebore adding a caricature of myself, so the illustration is just Gizmo. Underneath I wrote "My final thank you is to Gizmo the cat, whose gentle disposition and playful nature materially assisted me during the writing of this book."
Or something like that. At first I thought it was a bit soppy thanking a cat, but I figured, why not? She worked hard keeping me from burning out on this project, she modeled for the cover, and she was a great stress reliever.
So she gets a thankyou at the end of the book.