For Navi, the left cat, we call her Chunka Munk, Plasticat, and Ms. Infected Lips.
For Scorpi, the cat on the right, we call him Mr. Small, Spider Cat, and Crybaby.
I grew up next to a Norwegian neighbour who called our cat "Kattepus", and I have apparently picked up and kept the habit of referring to my own cat that way. He's also called Baggy, because being a black cat everyone wanted me to name him Bagheera