"Didn't know I sang, did ya?"
Jerry's an old crow who was accidently revived by Seymour Cheese a number of years prior to the show's starting point. Because of that act, he offers the services of himself (as an advisor) and his Ninja Crows (as cannon fodder). He constantly has to put up with the Big Cheese's crossdressing and explosion habits.
Jerry is the larger threat; he has the brains to carry out plots that the idiotic Seymour comes up with (and he'll come up with plots on his own, too), and every now and then he makes an appearance somewhere in the city. In the end, though, it always comes down to where and when the crow is whenever the Big Cheese self-destructs. Sorry, Jerry!
He's bald, and he doesn't know why birds can have hair on their beaks. And as evidenced by the quote, he can sing.