I use a couple different naming conventions.

I always wanted a "bigger" snake named Kitty, partly because it'd be funny. Therefore when I got my coastal carpet, that's the name that went to her. I hope to pair her up with a jaguar eventually and produce kittens

My other pets are named either after futurama characters (Morbo, Dr. Zoidberg, Edna, etc), because of identifying physical characteristics (Pongo the dalmation crested gecko, RG/Red Gecko, Sandy), or because of events (Accident).