I heard one that said that if you name Dagger Rally Ho or whatever after you get out of ice cavern that when you get to Condei Petey that you'll get to see Zidane's evil twin.

This of course was a load of bs because I tried it (and felt incredibly stupid afterwards) and there isn't even enough space to put Rally Ho so I had to go through half the game (or until I found the Nemingway card) with her name being RallyHo. So my advice is to NOT listen to these rumors.