Tutu Concept Art

This is Sailor Cygnus' alien pet guide, Tutu. She's a duck. (Obvious name reference!)
Tutu is from a planet on the Cygnus constellation back before they were engulfed in flames by Queen Betelgeuse. When the princesses of each of the planet used their powers to create a star seed and send it to  a far away planet (Earth), Tutu was sent along with it. She ended up losing track of the star seed. The star seed was reborn into Olive, and  around 15 years later, Tutu finally found the one with the Cygnus star seed inside them. Thus Sailor Cygnus came to be!