My dog, before he passed this past Monday, had a million nicknames - his name was Buddy but we called him Bobo, Buddo, Budfriend, Bubby, Bub, Air Bud. The list goes on.
My horse's name is Ringmaster but I typically refer to him as Ringo. Other names are Slim Jim, Jimbo, Jimmy, Spaz, Cripple, and $*&%!! (only when he's being bad).
Octavius is most referred to as Octo or Spazz.
Hestia, dear Hestia, has no nicknames. Poor girl.
Octavius - Male Halfmoon [02/19/11]RIP
Nero- who had been living under the moniker of "Hestia" for the past two months. Poor boy. [02/28/11]