Peter lives in the gutter with normal rats for almost a year to keep a low profile, but even within the simplified worldview of his animagus form, he’s aware that living off garbage sucks
He’s lowkey aware that he deserves that and worse, but he’s never really been the type to play martyr
And he’s not too far from Ottery St. Catchpole so he basically goes wandering around until he finds a wizarding house with children
Rat or not, he’s always been pretty good at ingratiating himself
And he feels a little sympathy for the skinny four year old whose older brothers don’t like to include him in their games
Plus Percy is really good about keeping his cage clean and not squeezing him too hard
So Peter’s like, you know life could really be much worse
Percy originally names him Milliphutt after an old Minister of Magic, but his bedraggled appearance leads Bill to coin the nickname “Scabbers” which basically everybody except Percy uses exclusively
Peter likes being Scabbers. It’s simple– and after all the years of his young adulthood, what he craves is simplicity. No one’s dying, no one’s life is in his hands, the weightiest decision he has to make is whether to sleep in a corner of Percy’s bed, or on the little pillow designated for him on the window sill
You don’t spend twelve years pretending to be something without becoming it at least a little
And for the most part, Peter actively tried to forget his past as a human. He wasn’t looking for an opportunity to flee the country and start his life again, he was trying his best to live in utter denial of his human life
He gets handed down to Ron when Percy gets an owl for being made prefect
Ron feeds him sweets more often than Percy, so Peter can’t complain
He means what he says in PoA when he talks about having been “a good pet”
Merlin knows there wasn’t anything else left for him to aspire to