There really are no rules when it comes to naming your pet. That is a reason why coming up with potential pet names can be so fun. There are no societal pressures for normalcy with pet names and you won't have to worry about your pet being teased at school, so enjoy the freedom.
While it's great to entertain thoughts of crazy and creative pet names, there are also a few practical things to keep in mind. Try to think of names with one or two syllables so your pet can recognize it more easily. Also, try to avoid pet names that sound similar to commands you may want your dog to know.
One popular way to come up with potential pet names is to wait a few days to observe your new pet's personality, appearance and tendencies. A name might pop up that fits your new pet perfectly. A fun way to twist this around may be to think of pet names in direct contrast to your pet's personality or appearance, such as giving your little Maltese a name more associated with tougher characters like "Spike."
While there's plenty of advice out there for coming up with pet names, just be sure its something you'll feel comfortable calling out for hopefully the next decade and more.