Enter the following names at the "Familiar Rename" screen to have the game automatically give you a new name.
Leave the name of any familiar blank to have it renamed to "No Name McGee".
Name your Ragamuffin Imp familiar "Tatter" to have it renamed to "Spoiler".
Name your Exotic Parrot familiar "Polly" to have it renamed to "Unoriginality".
Name your Blood-Faced Volleyball familiar "Wilson" to have it renamed.