We've been through that already.
It's a typo. It should be plea, not pea.
No, no, it's "pee", misspelt.
The police surrounded him and peed on him, demonstrating to him that he really is as lowly and pathetic as he was screaming about all day, so he gave up.
Now, returning to the actual story, think about how lowly this guy turns out to be: he goes nuts, charges the rhinoceri (who ignore him), climbs a tree and screams epithets at people all day because he can't get a job, has the police coax him down, and doesn't even get charged with anything.
So, not only can't he get a job or persuade the police to arrest him, he doesn't even have the presence to be able to anger a pair of rhinoceri when he's TRYING to do it.
This is the true meaning of nebbish!