Washu's not the only cute character in Tenchi Muyo, etc. Ryo-Ohki is an adorable cat rabbit (cabbit), with a later assumed semi-human form, and who even becomes a spaceship. Ryo-Ohki spaceships, who still meow, lay eggs to recreate themselves. Sasami befriends (a) Ryo-Ohki, and they spend a lot of time together... though the little cabbit seems to have a crush on Tenchi much like everyone else does. Sasami only has one other form, Tsunami. I don't yet have a cel of this older aspect of herself, though.
Episode #: Tenchi Universe 12: Adventures in Time & Space II
Stats: 3 layers, stuck, A1 & B4 KEY, C3 KEY END
Background: Unstuck, not sure if it matches
Comments: Sasami and Ryoohki are help at a restaurant in another world. I'll need to look over this bit again, as I can't remember exactly what's going on. Barring that Kiyone had just been brought in to begin working there, and was getting introduced. Because it was so adorable, this was one of the first two Tenchi cels I bought (the other was the blown-up Washu).
Episode #: TV
Stats: 1 layer, A6
Comments: Not sure when this happens, but I couldn't pass up on something this silly looking.