The strip centers on an eight-year-old boy named Billy and his best friend Cow, who live on Billy's family's farm. Other characters include Billy's father, his friend Martin, and his tutor Smart Billy. Billy's mother and sister have also appeared in previous runs of the strip. The strip often employs surreal humor, with bizarre recurring gags such as "cat-copters" (cats which dive out of the sky and knock people unconscious). Ongoing themes include: