Cat of Honour
She took care of Adri while she was bed-ridden (read: she kept coming into the apartment), and Adri took care of her gross, festering wounds while she fought in the streets every night to keep this world safe(?). And now they are here on this journey together, many stressful meals and 20 pounds later...I won't tell you how many of those pounds are Mona.
Local Cryptid
A being who clearly doesn't understand how to human. Child, let me explain, you are supposed to find a mate, get married, and have offspring, THEN get a house! But no...Adri just does what she wants. And so we are here today. When asked what the three extra rooms are for, she responds with some variation of "A library, Mona's room, and Mona's other room, of course."