"Bohemian Rhapsody" by Queen is quite an Ear Worm. Pretty much everyone can recognize the distinctive and complex melody, most people know the lyrics (at least approximately), it's a melding of numerous musical genres from rock to opera (thus lending itself nicely to being played with using other genres as well), and it also has a rather famous and recognisable music video. As a result, thanks to its distinctive nature and Small Reference Pools, it's become quite a common subject for Parody.
There are several common approaches. The first is to keep the melody more or less intact but change the lyrics to suit a new, comic purpose. The second is to keep the song more or less the same, but have it sung by unlikely or inappropriate stand-ins for Queen (such as the crew of the U.S.S Enterprise) or in much sillier or inappropriate voices, and a third is to keep the lyrics the same but change the melody from a dramatic fusion of rock and opera that something a bit less... bombastic. Then, once you're done, all you need to do is replace the 'Bohemian' part of the title with something more appropriate to your current purposes so that the title becomes "[X] Rhapsody", and bingo! Instant hilarity!
Since any of these options allow for endless fun to be had with the song, it's a popular target for fandom parodies. Of the different sections of the song to parody, popular ones include the 'ballad' section ("Mama, just killed a man...") and especially the 'opera' section ("I see a little silhouetto of a man" to "Beelzebub has a devil put aside for me for me, for me!").
While the song is subject to numerous parodies, the music video for the song is itself quite well-recognised and thus also subject to frequent parodies and visual homage. The stock visual parody in this case is the instantly recognisable image of four people arranged in a 'diamond' formation against a dark background, with the lighting arranged to suggest that their heads are disembodied (an image frequently used through the video, taken from the cover of the band's second album).
- A variant: Wayne's World has Wayne and Garth singing along as the song comes on the radio. Thus warranting another version of the video with scenes of the movie.
- Done with the British Royal Family in the Spitting Image sketch song "We Are The Royal Family", which is musically a parody of "We Are the Champions", but shows the Royals' heads with the same positions and lighting as Queen's at the start of their music video.
- An episode of Father Ted features the hyperactively annoying Father Noel Furlong subjecting everyone he's stuck in a cave with to an impromptu solo rendition of the song in which he does all the parts himself.
- Bohemian Polka from "Weird Al" Yankovic is an inversion in that lyrics are unchanged, but it's re-arranged to be a polka.
- "Rap Soda y Bohemia" by Molotov.
- Nintendohemian Rhapsody by Brentalfloss and Pat The NES Punk.
- Bluegrass Rhapsody original lyrics and music, but played as Bluegrass by Hayseed Dixie.
- Bohemian Rhapsody by Richard Cheese and Lounge Against the Machine (again original lyrics -more or less - and music but played as Lounge music).
- Jamaican Rhapsody by Ronald Reggae.
- At a show in Canberra, Australia, Ross Noble was delighted to discover that an audience member in the front row worked for the Australian Bureau of Statistics: the government agency that,amongst other duties, conducts the 5 yearly national census. Ross then ad libbed a lengthy bit where he was a census taker asking an imaginary person a series of questions, and then repeating their answers back; the answers gradually building up into the lyrics of "Bohemian Rhapsody".
- Star Trek Rhapsody
- Brohemian Rhapsody, done by CollegeHumor.
- Midichlorian Rhapsody
- Battlestar Galactica Rhapsody (warning: spoilers!)
- The Muppets did a version which Kermit says was a videoconference gone wrong.
- Zero Wing Rhapsody!
- Novocaine Rhapsody, a fusion of "Bohemian Rhapsody" and Green Day's "Give Me Novocaine."
- An old issue of Dragon magazine had "Companions' Rhapsody", sung by the cast of the Dragonlance Chronicles.
- BoHeman Rhapsody
- "Wal-Martian Rhapsody" by Mr. Wompy narrates an unpleasant trip to a Walmart.
- "Full of Himself Rhapsody" by Below Average Dave describes a man with excessive pride.
- Lost Rhapsody
- Titanium Rhapsody
- Epic Rap Battles of History referenced it briefly when Freddie Mercury battled Frank Sinatra.
- Not Always Right: A rather spontaneous outbreak of the song in a doctor's surgery waiting room is outlined here.
- The finale of the Super Mario Land flash series at Newgrounds ends with Mario escaping the dungeon set to the second half of the song, as shown here: 
- Well, it seems someone has finally done the unexpected... and created the Sega Saturian Rhapsody.
- Bohemian Gravity: A grad student studying string theory explains what it's about.
- Most Popular Rhapsody In School, for The Most Popular Girls in School.
- Google Translate Sings has done a version.
- Ultra Fast Pony has the bonus video "UFP sings Bohemian Rhapsody". Nearly all of the cast sing along (for a given value of "sing"), and they change the lyrics to be more pony-centric. Also has exaggerated Artistic License Music, with none of the musical instruments in the video matching the ones in the song.
- An episode of Caddicarus- specifically his review of LSD: Dream Emulator features a brief version of the song with 4 of Caddy's heads singing "Is this the real life?" shortly before slowly fading into an uncanny face from the game.
- Zuko-hemian Rhapsody.
- Calculus Rhapsody, where the singer briefly summarizes calculus, while making fun of it.
- Recreating the soundtrack cover with different franchises isn't unheard of - examples include, but are not limited to, Touhou (here), Jojos Bizarre Adventure (here) and (here), Kemono Friends (here), and even Transformers (here). There's also one featuring a set of pomeranians here.