Fry gets called Fryburt or Bubba-F.
Nibbler gets Niblonion, Nibs or Bubba-N.
Patch gets called Bubba-P, Fatso or Minky. (He's rather chubby and is always mucky). The OH calls him Pie sometimes, as in "who ate all the pies?!" Again, because he's a little chubster.
Sneezy get Sir-Sneeze-A-Lot or Bubba-S.
Collectively they get called the Bubbas or the piggies. If I'm speaking about Fry and Nibbler, they get called the Big'uns (even though they weigh less but they are older) and Patch and Sneezy are the Little'uns.