Jaffa and Mosi get called all sorts of silly names and variations on their names. They do change over time.
Jaffa - Jaffy, Jaffy Waffy, Jif, Jaf, lamb, poppet, gingerbread man, cuddles, stripey paws, stripes, tiger, sausage, mr man
Mosi - Mosi wosi, Fluffy, manic mosi, nosy mosi, lamb/lambkins, fluffpot, little lemur (cos I he looks like one), little lion (cos he thinks he looks like one), His Mosiness, munchkin, mr fluffly paws, squirrel nutkin, bonkers boy
Come to think of it, it's amazing they know their proper names! (which incidentally are Jaffa Cake Stripey Paws and Mosi Hobgoblin)