Mine is after a dalmatian puppy I had (years ago) that passed away. His name was Pepper. The W is for my last name. The 23 was random haha. I have also been known to use W7Scraps after my current doggie on other boards.
I wanted to come up with something clever and definitely Disney-ish, but I just couldn't do it quick enough when I signed up, so I use the name I use on other boards, ThreeAngels, and it's for my 3 wonderful children.
Mollygirl was a Boston Terrier I had growing up. She was such a great dog! I was so sad to see her cross the Rainbow Bridge 2 years ago at the age of 12. So I chose her name to remind me of her everytime I log into the Dis.
13 is my favorite number (DH and I were both born on the 13th)