You know who they are, right? (uhoh - short break to dance with wild abandon to Morris Day and the Time on the Grammys) Of course you do. They're both terrific Tim Burton characters: Zero the ghost dog from "Nightmare Before Christmas," and Scraps the bone-puppy from "The Corpse Bride."
I was reminded of them today as I watched "Nightmare," because I love Zero so: all dog, all heart. Though a search for Tim Burton didn't bring up anything he himself had to say on the dogs he's loved that inspired these great characters, here's a fansite article that will do just fine.