I've often wondered if the folks at KI sometimes add secret bosses/areas with the sole intent being to monitor them to see if anyone ever finds them. No warning, no heads up, no clues... just a lonely, unmarked door somewhere that leads to potential mounds of goodies. If I was a programmer that's what I would do... but I'd be tempted to throw some clues in. And maybe a "First to Find It" type of badge too. It would be a way for players to get a one-of-a-kind badge! It's fun to think that somewhere in Pirate or Wizard there might be undiscovered areas somewhere in the game.
Well, those all sound nice, but the "First to Find It" badge type... I wouldn't use it. Would only create competiton over who gets to discover more secret bosses.
I'd rather stick with the best at making secret bosses, if you were a programmer. Challenging, yet reasoning to specific levels, custom-made unique loot drops, cheats, secret bosses' dialogue from encountering & defeating them, unique badges, & such.
Hope once the next story update goes out, we should ask KI to add more secret bosses to P101.