Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a biography of a phony musician named Dewey Cox that spoofs lots of famous musicians, especially Johnny Cash and the music biopic about him "Walk the Line" (2005.)
When they were young boys, Dewey Cox listens to his brother Nate talk about how they're going to have long and fulfilling lives because the great thing about being young is that there's so much time to do great things. Then they proceed to tempt fate as young boys do by teasing a bull, playing with a rattlesnake (Nate picks up the snake with his bare hand then throws it at Dewey), riding a horse, driving a tractor, using a welding torch, and fighting with machetes. The day does not end well for Nate, but for once in a movie, it wasn't the rattlesnake that kills him.