Beavis and Butthead in Scared Straight

Hoping to have his students stop causing trouble, Principal McVicker restarts the "Scared Straight" program, picking out several students from a yearbook, including Beavis and Butt-head.

However, this backfires as they were horseplaying during the booking process and slapping each other with fingerprint ink-stained hands. Then an inmate with a prosthetic leg and glass eye tried to intimidate them; although Butt-head was initially scared, Beavis is still smiling and laughing.

As Butt-Head sits on the toilet within a jail cell, Beavis and 2 inmates are taunting him, which Beavis notices that one of the inmates has a tattoo of Iron Maiden, which instantly prompts the four to form a bond.

Much to the chagrin of the warden, he finds the four singing The Prisoner, prompting him to have the duo leave, but not before Butt-Head expressed a desire to return to prison to party with the inmates, and Beavis telling them to look them up once they are released. As they are about to board the bus, they notice another group arriving and sneak back into prison with them, with Butt-Head saying "prison is cool".

Read more here: https://beavisandbutthead.fandom.com/wiki/Scared_Straight