My snakes are generally named for "lesser" or obscure characters in favorite TV shows, movies, or video games. LOL! There are a few exceptions, though. For instance, my three yearlings from my 2013 clutch are all IndyCar themed... because my (at the time) two-year old son named the first one "Racecar" right out of the egg.

(On that note, one of those three snakes is still technically unnamed. I've been calling her by a name... but I don't like it and haven't come up with something better. Heh.)
Reggie - Raiders of the Lost Ark (the original snake on a plane)
Una - Stardust
Tael - Zelda: Majora's Mask (used to have a sister, Tatl)
Celia - Monster's Inc.
Juju - The Princess and the Frog
Envy - Scott Pilgrim vs. the World
Roxy - Scott Pilgrim vs. the World (from my very first clutch... she was baby #4)
Rayne - webcomic character
Tippy - Pixar short "One Man Band"
Racecar, Dallara, & "Taku" - IndyCar
Nag (MBK) - Rikki Tikki Tavi (my husband named him)
As for the other pets...
My cats (Whitacre & Ticheli) are named for favorite concert band composers.
The sugar gliders are named using magic as the theme. Our first pair was Penn & Teller. (Penn has since passed away.) Then we added Elphaba, Fiyero, and Glinda.
Morgan, the dog, is, uh, named after Morgan Freeman. Because as a puppy in winter we would take him outside and he would sit on our feet, so we joked that he was a penguin puppy. The only penguin film we could think of was March of the Penguins, narrated by... Morgan Freeman.
Back when I had pet rats, they were all named for characters out of Orson Scott Card books... specifically the Ender's Game and Ender's Shadow series'.