Judas Wriley - Rattus norvegicus - 22 years
"Jude" is the starring ratty whose introspective musings can make the world seem like a very poor place in which to live.  In truth, he's just a former optimist trying to find his niche again and that search can come across as bitter resentment.  He lives "by himself" with his roommates.  Jude doesn't talk about his family much but apparently he's the oldest of three.

Joshua Davis - flea of undetermined age and species (not a rat flea)
Joshua pops up from time to time, in an effort to help Jude out.  He was sent from somewhere much to Jude's chargrin.  He and the ratty seem to have some sort of "history" together.