I saw some unused Popo designs before. His introduction where he completely dominated Goku after the triumphant battle with King Piccolo was pretty cool, so I wish we could have bird/lizard designs instead of this one that needs to be buried.
Jiren grew on me for its simplicity. Take a common alien design that's usually wirey and take it in the other direction. I also particularly like the Pride Trooper's uniform.
Someone mentioned Super Buu, and a detail that's lost in the manga is the hands. In the manga, Buu's hands develop more as he absorbs more people. Fat Buu has gloves for hands, then until he's absorbed Gohan, some of his fingers are still not fully distinct from palm. Like Piccolo growing an extra finger in the anime, it's probably because censors/studios are sensitive about people whose hands might invoke yakuza.
