We have a California king snake; she ran away (well, the kids let her out) last year, but she came back. Which was kind of a pleasant surprise (though it was winter time, and the house is a LOT warmer than the outside). There she was, in the stairwell, helloooo snake!

She was a gift from a herpetologist I used to work with -- she was a byblow from a hybridization experiment, so she's recessive for a lot of interesting things but predominantly looks almost exactly like this bog-standard king snake here.

Her name is Spot.