The Movie of Beavis and Butt-Head. After the duo wake up and find their TV stolen, they scour Highland in search of a replacement. Their quest results in the pair stumbling onto a murder-for-hire plot, a cross-country trip to Washington DC, and the federal government's most wanted list. You know, the usual.
Beavis and Butt-Head Do America contains examples of the following tropes:
Bittersweet Ending: The boys don't get any money and fail to score (as usual), but they do get their TV back.
Bolt of Divine Retribution: The boys get struck by lightning after posing as priests in a confession booth (and mistaking said booth for a portapotty). They don't even notice it.
Bowdlerise: After Sept. 11, public TV showings of this movie cut out the part where Beavis' Cornholio antics nearly cause a jetliner to crash. Also, instead of assuming the boys to be terrorists, Fleming calls them "masterminds."
Though in a way, for a professional government agent to be considering Beavis and Butthead smart enough to be masterminds is pretty damn funny in and of itself.
Butt Monkey: Tom Anderson, as usual. Along with Van Dreissen, who gets taken down by ATF agents in painful fashion for his connections to Beavis and Butt-Head. And, of course, there's Beavis and Butt-Head themselves.
Iron Butt Monkey: Frankly, given everything that they end up going through, it's a wonder that Beavis and Butt-Head came out alive at all.
Circling Vultures: The boys, lost in the desert, see vultures circling them overhead. Even in this dire situation, the boneheads still take the time to "huh-huh!" when they see a pair of vultures "doing it".
Cool Old Lady: Beavis and Butt-Head literally have this opinion of an old woman they befriend on their plane to Vegas (and on the subsequent bus trip across the country) when they think all of her comments apply to a rich sexual history.
Darker and Edgier: While the film still has comedic beats, the plot eventually becomes more serious than any other episode of the series. A criminal confuses Beavis and Butt-Head for a couple of hired thugs to kill his girlfriend, who ends up using Beavis' pants to hide an extremely dangerous biological weapon, which prompts the ATF to go after the duo. In numerous cases, Beavis and Butthead fell into mortal danger. (Hell, the film even featured more blatant sexuality than the entire original series combined.)
A Date with Rosie Palms: Beavis has one in Anderson's camper. And it's implied BOTH boys have done this in Anderson's camper and tool shed in the past.
Muddy and Dallas Grimes finally meet again, but Dallas charms her way into not getting Muddy to kill her by tempting him with sex. The camera is just far away enough so that you can't see their genitals touching.
Of course, considering all the damage that Beavis and Butthead unwittingly cause, they could easily fall under this trope, as well.
Knight of Cerebus: Muddy and Dallas Grimes; in most of the scenes where they appear, the movie loses its comedic beats and focuses on the dramatic.
Luke, I Am Your Father: The boys meet their biological fathers while lost in the desert. Due to their complete idiocy, none of the four ever realize it.
MacGuffin: The X-5 Unit, a viral bio-weapon that could wipe out five states in five days. And guess which moronic duo end up carrying it without ever realizing it?
MacGuffin Delivery Service: Dallas Grimes plans to use the titular duo as an unwitting example, sewing the MacGuffin into Beavis' pants and telling him and Butthead to take the bus to Washington D.C., where she intends to meet them.
Mike Nelson, Destroyer of Worlds: While Beavis and Butt-Head never actually destroy the world—which is seriously saying something, considering these two were carrying a dangerous bio-weapon for two-thirds of the movie—their Chaotic Stupid nature leads to them inadvertently:
Nearly crashing a jet-liner.
Flooding the area around the Hoover Dam when they unwittingly sabotage the control system.
Blacking out all of Las Vegas with the aforementioned Hoover Dam Fiasco.
Causing a major traffic accident on the freeway when they do some unplanned body-surfing across the road at 60 MPH.
Causing many witnesses who saw them in passing, along with acquaintances like Van Dreisen and Tom Anderson, to get subjected to intensive grilling by the ATF.
Just to reiterate...inadvertently. Beavis and Butt-Head had no freakin' IDEA that they were DOING any of this, let alone that it was even HAPPENING half the time.
Mind Screw/Mushroom Samba: Beavis eats a peyote cactus in an attempt to prevent dehydration, but this results in a nightmare hallucination set to the tune of Rob Zombie's "Ratfinks, Suicide Tanks, and Cannibal Girls".
Mistaken for Terrorist: Beavis and Butthead, due to being in the wrong place at the wrong time. Mr. Anderson also falls into this situation at the very end.
Running Gag: Agent Fleming's obsession with giving everyone cavity searches leads up to an inevitable punchline when Butt-Head says "Did I just score?" after receiving one himself.
Scarily Competent Tracker: Muddy does what the FBI cannot and manages to track down the boys after they've passed out in the middle of the desert.
Tempting Fate: An unwitting example. After exposition on the X-5 bio-weapon—such as its flawed casing, which could break open and release the virus if hit hard enough—Agent Fleming concludes his marching orders to his men with "Let's just pray that nothing hits that unit." Cut to a tour bus, where Butt-Head is repeatedly kicking Beavis in the seat of his pants—exactly where Dallas hid the X-5 Unit.
The Vamp: Dallas uses her good looks and the boys' obvious lust to smuggle her stolen bioweapon across the country.