Intriguing. It's clearly not the type, flavor text, abilities, set, or artist. I can't find any unifying theme in the artwork. That leaves the name. I bet it can be solved just looking at the list, without knowing anything about the cards... but I can't get it. My best guess is that it has to do with another cultural product that I'm not familiar with, such as "shares a name with a card in Game X" or "shares a name with a chapter in the X series of books" or something.