Ours are not exactly Halloween names but spooky.

One of my bunnies is named after Lily Munster- she's a sweet looking albino New Zealand who often exhibits behavior much like the white rabbit in Monty Python's Holy Grail. We had to get her a littler box made for dogs because she keeps tearing her boxes up. I trained her out of biting for the most part, but she is a growler (yes bunnies do growl) and a snorter and a lunger, and likes to attack the vacuum hose... So we sometimes call her Cujo. Or, for titles, Lily M. Cujo.

My other rabbit is Rasputin, Black Rabbit of Death. He's a huge solid black California/NZ mix who is so Zen and noble it's not even funny.

I have the yin/tang of the rabbit world there.

Then we have two rats - Anne Boleyn - she is all white with a black head, and when you see her running around on a dark background, she looks headless.

And the other, an albino rat who we named Queen Elizabeth but because of her tendency to bite, which I've decided is blood lust, we call her Countess Bathory now. (Yes I know, according to all accounts and research Bathory didn't actually drink blood, she bathed in it, but you get the point. )

And my hamster's name isn't scary or Halloweenie, it's Monsieur le Pouf.