Beavis and Butt-Head
X5 unit

The unit, being thrown airborne.

The X-5 Unit is a biological weapon that appears in the movie Beavis and Butt-Head Do America. Dallas Grimes (an arms dealer) steals the weapon, then encounters Beavis and Butt-head in a hotel room in Las Vegas after her husband, Muddy, has mistaken them for a pair of hitmen he has hired over the telephone to assassinate her.

When the ATF tracks down Dallas, she hides the X-5 in Beavis' underpants to avoid being caught with its possession. She then tells Beavis and Butt-Head to meet her in Washington, D.C. Throughout the rest of the movie, Beavis and Butt-Head are oblivious that they're carrying a deadly weapon; the only clue being that it is making Beavis' butt itch (He continues to scratch his butt throughout the movie).

The ATF learn that Beavis and Butt-Head are in possession of the weapon, thus causing the two to become wanted criminals. Muddy Grimes (said husband of Dallas and also an arms dealer) also seeks the weapon. Muddy finds the boys unaware that it's inside Beavis' pants. Eventually, Beavis and Butt-Head make it to Washington, and before Dallas can meet up with them to recover the weapon, she is confronted in the parking garage by Muddy, who demands to know where the X-5 is. Later, Muddy and Dallas are arrested by the ATF. Faced with the possibility of a 60-year jail sentence, Dallas betrays Muddy, telling the ATF that she previously secreted the weapon "in some kid's pants". While masturbating in Mr Anderson's camper, Beavis is caught and thrown out without his pants. Tom Anderson then opens the camper door, telling Beavis to take his pants with him - ejecting them out the door, which causes the ATF to hurriedly go after them. The underpants are ripped open in the melee, with the consequence that the X-5 flies out of them. It lands safely in Butt-Head's hand, and not knowing what he has, he decides to give it to the ATF. The X-5 Unit is recovered, Anderson is accused of being Muddy and Dallas' accomplice and is subsequently arrested. Beavis and Butt-Head become heroes.


  • Beavis and Butt-Head never knew what the X-5 Unit was. When the ATF demanded Beavis and Butt-Head to "hand over the Unit", the boys think the ATF wants to see their penis.
  • Agent Bork stated that the X-5 Unit was an incomplete weapon because Dallas stole it while the Unit was being made.
  • It is unknown what Dallas wanted to do with the unit, yet from what she was telling Muddy, it could be assumed she was going to sell it to a foreigner at the conference or perhaps just set it off.