When I went to school, one kid during that exercise said that his name was so-and-so, and one thing he liked to do was stick his thumb up his ass.
He was known as “Thumbs” for the next four years, possibly longer. I actually don’t think I ever learned his name, he was just Thumbs.
I knew a kid who was caught beating his meat on a school trip, and was thereafter known as Spanky.
Surely older than 4th grade, puberty for boys tends to not happen until 6th or 7th grade.
Yep, it happened in 8th grade so people called him Spanky through the end of high school.