Shugo Chara Doki!! Episode 3 - X Eggs are *so* last season
Of course, once I finally get caught up with Shugo Chara, the latest episode is late. And of course that episode would be the first actual plot-related episode of the season (the first two were glorified recaps). This season's enemy was revealed, along with the ? Egg. As Yaya points out in the image, if the first season eggs were called X (batsu, or wrong, as in a wrong answer) Eggs, then this season's eggs are called ? (nazo, or riddle) Eggs.
That just makes me think of if this scene were dubbed, the eggs might be called Why Eggs, with Yaya explaining that since it's not an X Egg, it must a Y Egg. But maybe that's just me.