One of the warlocks in the party scene is wearing a gold lamé outfit worn by Conrad Birdie in "Bye Bye Birdie", which Paul Lynde (Uncle Arthur) starred in both on Broadway and in the filmed version.
In addition to appearances in baseball documentaries and on talk shows, Willie Mays appeared in several sitcoms over the years, always as himself.
The title is a variation of the Halloween expression "Trick or Treat" which was used as the title of another Bewitched episode.
The Star Trek (1966) trekkie would tell the Bewitched (1964) fan: "He was the ORIGINAL 'Surak' - founder of Vulcans and Vulcan Philosophy." Barry Atwater played "Boris" who went to the Halloween party with the black cat disguised as a woman. Barry Atwater was the original 'Surak' in The Savage Curtain (1969). However, it would be three years until he played that immortal role. Note: He must not be confused with "Sarek" (played by Mark Lenard) - Spock's father. In short, Barry Atwater who played "Boris" was and is a big name to Star Trek fans.