I know how to do this, by taking a Mon Calamari who isn't Admiral Akbar to the floor.
What I want to know is if this simply requires luck.
I do not get ? bitizens who are Mon Calamari, only Akbar. I have unlocked the species and have them living in the Death Star but I've not managed to unlock the Scene because I haven't had one request the floor the aquarium's on as their appearance is relatively rare.