you know their names by looking on the character chart. you can find that in the library section on tamatalk.actually, no tamagotchi that are on the character chart are rare. the only rare ones are nazotchi and the debugged secret character. that is all. no characters in the character chart are rare. it is because some people never gotten it and say it is rare. there are a whole bunch of tamas now, so there is a little chance that you will get a certain character.