Who is Punky Holloway from The Man Who Loved Clowns and what is their importance?

Punky Holloway is Delrita's uncle. Punky was born with Down's syndrome, a disorder that has left him handicapped and unable to live on his own. Punky is described as having a moon-shaped face, almond-shaped eyes, doughy white skin, and a thick tongue that seems to be too big for his body. His appearance is very similar to most other people diagnosed with Down's syndrome, yet it often elicits mockery and taunts from strangers. Because Punky is mentally retarded, he doesn't understand when people are laughing at him, and he sometimes joins in, which drives Delrita crazy, and she has made it her personal mission to protect Punky from the many bullies in the outside world. Even though he is in his thirties, Punky still acts very much like a child. He wears a cowboy hat, sings into an imaginary microphone, rolls broken crayons on his table, throws chicken bones behind the television set, and loves watching advertisement commercials. He's so different that Punky's legal guardians, Sheila and Sam, have raised him solely at home, never sending him to school and never sending him to the sheltered workshop where many other handicapped adults spend time. When Shelia and Sam unexpectedly pass away, Punky is sent to live with his brother Bert and his wife, Queenie. Bert and Queenie opt to send Punky to the sheltered workshop despite family pleas. There, Punky discovers that he loves work. He makes friends - even a girlfriend - joins the Special Olympics, and has a sense of pride and self-worth. At the end of the novel, Punky suffers a heart attack and dies, leaving Delrita to mourn his death and learn what she can from Punky's life lessons.