I'll just make this a story-within-a-fanfiction and cast the All Dogs gang as different OCs, which Charlie tells to his puppies (those created by ).
CHARLIE BARKIN as BARKY CHARLES (this comes from where in Peanuts, Peggy Jean calls Charlie Brown "Brownie Charles," which he unintentionally introduced himself to her as), the main character. He is a selfish detective who intends to get Eudemonia to be his girlfriend, but she rejects him for his selfishness, but eventually, he learns to have a heart.
ITCHY ITCHIFORD as Barky's so-far unnamed partner.
SASHA LA FLEUR as EUDEMONIA JACQUEFILS (this last name comes from being a made-up French equivalent to "Jackson," as "Jacques" is an equivalent to "Jack" and "fils" means "son" in French, which is due to Sasha's last name being in French), Barky's love interest who doesn't fall in love with him.
FRIGGA -, the main antagonist. Completely original.
ANNABELLE THE WHIPPET ARCHANGEL as a voice of reason to Barky.