Nixon Mask

"I knew it was you all along, Richard Nixon!"

—Officer Barbrady, South Park

As might be inferred by the title, a Nixon Mask is a rubber mask with the characterized features of Richard Nixon, specifically a large nose, and creepy wide grin. See it in profile here.

Its status as the best-selling political mask of all time (and in many ways the inspiration for all political masks), as a symbol of famous counterculturists like Hunter S. Thompson and Bob Dylan, and as a hilarious remnant of the seventies have made it a classic go-to prop when a strange/hilarious mask is needed.

Examples of Nixon Mask include:

Comic Books

Used by a group of convenience store robbers as a throw-away gag in The Dark Knight Returns. Note that this group predates Point Break (see below) by a full five years.
The Nun in Fell.
The gang of anti-clowns in Transmetropolitan.

Films -- Live-Action

Point Break (1991) is perhaps the canonical example, with its team of bank robbers each donning a mask of a former president, making it almost required for future criminal-themed media to reference it.

Bank robber wearing Nixon mask: I'm not a crook.

- Parodied in the French movie Brice de Nice, where the title character is obsessed with watching Point Break. When he tries his hand at his first own bank robbing, he's wearing a mask of Jacques Chirac.

Brice: Écoutezz [sic]... je ne suis pas un escroc.

In Airplane II, when the shuttle goes to "Worp 0.5", the stewardess warns that the passengers may experience some slight metabolic changes. It then shows every passenger in a Nixon Mask.
The robbers in Best Seller (1987).
The criminal in the B-Movie House on Highway 5 uses it as his scary mask of choice. It's actually kind of effective.
The Ice Storm: Wendy Hood (as played by Christina Ricci) wears one while seducing her neighbor in a prime case of Fetish Retardant.
The body in Men at Work is found wearing a Nixon mask.
A recreation of the Watergate break in the Spike Lee film She Hate Me has the perpetrators wearing the masks.
Worn by one of the cheeleaders in Sugar and Spice.

Literature

Worn by three characters who just happen to take part in the same shootout in Gone Bush by Chris Amies.

Live-Action TV

One of the characters in a group of friends during the episode "Blood on the Tracks" of Cold Case is seen riding a back and wearing a Richard Nixon mask... and apparently nothing else.
One appears in the Doctor Who 1996 Telemovie, while the Doctor is rummaging through some costumes looking for something to wear. Amusingly, the music gets kind of scary and he looks at it like it's pretty terrifying.
It also seems to be a popular disguise for streaking episodes: both Joey Gladstone of Full House and Eric Forman of That '70s Show have streaked in Nixon masks (the latter in front of Gerald Ford).
Will and Grace
- Jack McFarland's biological father wears the mask to hide his identity.
- Also, in the first Halloween Episode, in which Will and Grace get roped into babysitting Harlan's kids for the night, one of the kids is dressed as Nixon, with a mask.
An episode of Wings had a Nantucket bank being robbed by an unnamed criminal wearing a Nixon mask; however, he is later apprehended by Antonio and Brian.
Kamen Rider Kiva subverts it by having a robber in a George W. Bush mask in one episode. This may be Truth in Television; Bush was president at the time the show aired, and masks of him were very popular in Japan.
On iCarly the gang is trapped in psycho girl Nora's basement. They attempt to escape but are stopped by Nora wearing a Nixon mask and holding a hatchet.
One episode of Knowing Me Knowing You saw Alan Partridge complaining about a group of robbers who wore Alan Partridge masks.
Used in Underbelly: Tell Them Lucifer Was Here by Bandali Debs and his accomplices. Also applies to the real life robberies.

Music Videos

In the video for Bow Wow Wow's "Do You Wanna Hold Me" the guitarist rocks out in a Reagan mask.
The Manic Street Preachers wear the masks in the music video for "The Love of Richard Nixon".
One of the costumes used in The Residents' 13th Anniversary Tour was one of these.
In one of the shots in Billy Joel's "We Didn't Start The Fire" the kid of the couple is shown wearing the mask and holding a toy pistol.

Western Animation

Meatwad wears one for Halloween in Aqua Teen Hunger Force.
Hippie Teacher David Van Dreissen wears it for Halloween in Beavis and Butthead.
Family Guy
- Spoofed by having a man in the mask rob money from a charity car wash, and the attempts to report the crime derailed by trying to remember which movie he was referencing.
- Cleveland is snuck into a white's only golf-course using a Nixon mask.
Johnny Bravo: A shark attempting to pass itself off as human in "Beach Blanket Bravo" wears one. It goes surprisingly well.

Surfer: Wait a second. You're not a shark, are you?
Shark: Uh... no! I'm... Richard Nixon!
Surfer: Cool! Hey, thanks for getting us into China and everything! (does the V sign)

- What, you mean with that set-up he didn't say "I'm not a shark!"? Amateurs...
Worn by the "Chicken Lover" in the South Park episode of the same name.
In Squidbillies, worn by an aging stunt-hooker as part of rehearsing a sex scene with ~~a double-amputee con artist~~ Patrick Swayze.
Frisky Dingo: One of the X-tacles wore a Nixon mask.

Real Life

Etiquette Hell describes a wedding where "For reasons that were never revealed, the DJs put on mariachi sleeves and latex Richard Nixon masks(?!?!) before leading the conga line under the limbo bar [...] my date whispered to me: 'LSD could add nothing to this experience'."
Stories tell of a man who robbed a bank using one of these as a disguise; he was armed and it was a very serious situation, but still.