I only have a few that had shelter/foster home names:
Azrael was originally Pumpkin
PeeWee was originally Socks
Sammy was originally Nera (which I thought was a girls name. They could have at least gone with NerO
And Buddha, although not a cat, was originally Alex - which we considered keeping because it does fit him... but we wanted something that went well with Karma
Jack, John Doe, and Tryon adopted us off the street so they didn't have names that we knew of.
Karma came from a shelter, but she didn't have a name... only a number.