GBA #6: Jam Session pg 18
This is a reveal I've been sitting on for a long, long time. Like, since GBA started. I waited this long because I wanted to establish Cicero as a character, this way the fact that he's trans would be part of who he is, not what defined him. Jam Session's rapidfire storytelling made for a perfect time to bring it up.
Also, that Gastrodon in the top panel? That's the aforementioned Gaston Antwerp.