Zapulla is the consigliere of the Pavano crime family. He used to be a lover of the family's Don, Mary Valvona, and is suspected alongside her for poisoning the former Don of the family, Valvona's husband.
While Arthur was Maria Valvona's lover, she funded his schooling for his law degree. His license to practice law was stripped when he was caught in possession of drugs. Even though he doesn't practice law, Arthur still advises the family on matters.