Rack, Shack and Benny (their real names are Shadrach, Meshach, and Abednego) are the three protagonists in the episode of the same name, which is loosely based on the third chapter of the Book of Daniel. Rack is played by Bob. Shack is played by Junior. Benny is played by Larry.
The Real "Rack, Shack and Benny"
They are based on Shadrach, Meshach, and Abednego from the Bible story of the same name, found in the Book of Daniel. These were actually new names that they received when they moved to Babylon. Their original Hebrew names were Hananiah, Mishael, and Azariah.