From Norbert K@21:1/5 to All on Tue Jan 4 05:11:11 2022
Among the images chosen to appear on the Sgt. Pepper's cover is that of novelist Terry Southern.
Southern was the author of books including The Magic Christian, on which the 1969 movie, starring Peter Sellers and Ringo Starr was based. A Collection of his 1960s satirical short stories called Red Dirt Marijuana and Other Tastes came out in 1967.
If it was a Beatle and not Robert Fraser or Peter Blake who chose Souther's image, my guess is it was Lennon.