Here are three other TMS characters who have the same head as Wayne and Bobby Benson:
Roger (the guy who works at the Muppet Sound Studio in the Helen Reddy ep.)
The security guard outside Liberace's dressing room who was one of Steve Whitmire's first speaking characters (Liberace ep.)
The Howard Keel look-and-soundalike who sang "Close To You" (James Coburn ep.)
Also, Marvin Suggs is a Whatnot, and William Tell (Alice Cooper ep.) and Rugney Rogg (one of the cross-country billiard contestants in "Muppet Sports" in the Roger Moore ep.) share the same head with Marvin.
Then there's Bruno, the guy who works at the gold processing plant in the Shirley Bassey episode. He himself is a Whatnot, too. The Arab (Helen Reddy ep.), Svengali (Peter Ustinov ep.), and Bert (the British chap in the top hat who sang in the Don Knotts and Nancy Walker eps.) all have the same head as Bruno.
Also, Billy (Big Tiny Tall Saddle's assistant in the Johnny Cash ep.), Benny (from "The Cat Came Back", Linda Rodstant ep.), and Johnny (the young fiddler from "The Devil Went Down To Georgia", Alan Arkin ep.) all share the same head.
Pegleg (Glenda Jackson ep.) and Angus McGregor (the contestant from the bagpipe eating contest in "Muppet Sports" in the Anne Murray ep.) both share the same head.
Cynthia Birdley (Peter Ustinov ep.) and Zubin Backmesser (the conductor from the "Muppet News" segment in the Tony Randall ep.) have the same pink, Fraggle-ish head.
The doctor/witchdoctor from the "Coconut" number in the Kenny Rogers ep. was a Whatnot, and the Singing Weatherman (from the "Vetrinarian's Hospital" segment in the Gladys Knight ep.) and the jug-playing guy in Lobbuck Lou and his Jughuggers that Steve Whitmire performed in the Gene Kelly ep. share the same head with him.
Does that sound good to you?
BlueAM
"One day, lad, all this will be yours..."
"What- the curtains?"
"No! Not the curtains, lad... all that... all that you can see, stretched out over the hills and valleys... as far as the eye can see and beyond... that'll be your kingdom, lad."