"Elvis" sounds a lot like "elvish" and looks a lot like "elves", making for a comedically useful stock pun.
The incongruity between the decidedly ethereal and long-lived elves and the earthy and very much mortal
and hedonistic Elvis Presley
arguably just makes it funnier. Of course, some versions of elves are
earthy and hedonistic, in which case it makes an awful lot of sense. And sometimes this is all an act
designed to let them steal human children, which just proves the Moral Guardians
were right about that hip-thrusting Lothario the whole time
His immortal supernatural heritage may be used to explain his "disappearance"
; that is, Elvis is not dead, he just went
to the Undying Lands
Then again, sometimes there's no significance to it at all, it's just an Incredibly Lame Pun
For some reason, no-one ever makes these jokes about Elvish Costello
- An advert for Yellow Pages had a man at a fancy dress party dressed as an elf, surrounded by other people dressed as Elvis. He mentions that "[his] invitation definitely said elves, OK?"
- ElfQuest included one reference to "Elfis" at some point in a parody version of itself.
- The Elvis Impersonator Spellvis from Gold Digger isn't an elf, but his music is Magically Delicious to women.
- One of the earliest examples is Emma Bull's War for the Oaks, where the rock band has Elvish lead guitar and bass players, and a faerie roadie.
- In Soul Music, everyone keeps asking Buddy (a parody of every dead rock star, ever, but especially Buddy Holly)as, you know, Buddy's real name "Imp y Celyn" translates as "Bud of the Holly." if he's elvish. (Which is worrisome for Buddy in certain kinds of company, because dwarves and trolls have a standing blood feud against elves.) At the end of the book, after he's saved from an alternate universe in which he dies in a carriage accident, someone comments that there's a new guy working in the chip shop, and she could swear he looks elvish. In the Animated Adaptation, he looks and dresses like Elvis.
- A quick gag in The Shepherd's Crown, when the dying down of an elf's glamour and imperiousness is described as "the elvish was leaving the building".
- In The Dresden Files, Harry Dresden once went on a tangent on how more than one Elvis could be worded as Elvises and then noted how that sounded like he was talking like Gollum trying to say "Elves." Gentleman Johnny Marcone was more than slightly bemused and confused after hearing this particular tangent.
- He also once accused Thomas of dressing too much like fat end-of-his-career Elvis. Thomas is a vampire, not an elf, but White Court vampires have a similar too-pretty-to-be-human allure.
- The short story "The Return of the King" by Susan Wade and Don Webb.
- In Quantum Gravity, Zal does just about every genre of music, but is referred to as a rock star. And the incongruity earns him little love back home.
- Muppet Classic Theater: The last story is "The Elves And The Shoemaker". Rizzo the Rat exclaims "A story about Elvis?" Gonzo tries to correct him, but sure enough in the story, the elves all look and act like Elvis. And they make blue suede shoes.
- In the Due South episode "Gift of the Wheelman", where the robbery suspects are dressed as Santas, the police accidentally round up Elvis impersonators for questioning instead of Christmas elves.
- In The Nanny animated Christmas episode "Oy to the World", Fran and Brighton Sheffield meet Santa's chief elf Elfis, being played by Niles, who briefly impersonates Elvis in his first scene.
- MAD had a comic in which Santa Claus put out a Help Wanted ad for new elves, but it was misspelled and he ended up with a bunch of Elvis impersonators instead.
- In the Lord of the Rings Chilean parody "El Señor de los Ladrillos", the Elves became "the Elvis".
- A UK Christmas card has a queue of Elvis impersonators outside Santa's workshop, while he says to Rudolph "What did you write on the want ad, again?"
- Tom Smith did a rockabilly song called "Return of the King" about  Elf-descendant Aragorn chock full of Elvis gags and his usual atrocious puns.
- The Mark And Brian Radio Program gives us Elfis.
- The Magic: The Gathering card Elvish Impersonators. ("Elvish Impersonators" is also an Everquest guild, though it's unclear if there's any causal connection between the two.)
- Murphy's Rules (a compendium of nonsensical rules, funny errata and other game weirdness) included Elvish Presley in a list of annoying NPCs for players to encounter (along with Sailbad the Sinner and Uselysses).
- Kingdom of Loathing has "Elvish Sunglasses". Among other things, they give you the "Rock Out" ability while you're wielding a musical instrument. The Mysterious Island Arena also gives you the Elvish effect for 20 adventures if you choose the option Try To Get Into The Music.
- In Discworld Noir, Lewton will say "Thank you very much" with an Elvis accent when a wizard informs him that glamours are "an elvish thing".
- In Warhammer Online: Age of Reckoning, the player can grow Elvish Parsley.
- In World of Warcraft, one April Fools joke introduced the Bard class - a new hero class which would attack enemies via Guitar Hero minigame. Had this actually been introduced, one could have expected to find lots of Night Elf or Blood Elf
rockstars Bards. As a Shout-Out to this trope, the Bards on the World of Warcraft announcement were Blood Elves.
- Sig Nicious is an actual in-game bard of sorts, being the rhythm guitarist of the Warcraft mascot band Level 90 Elite Tauren Chieftain.
- My Sims Kingdom. Forest Of The Elves. One is your classic wood elf, the other IS A ROCK STAR!!!
- Serious Sam II has planet Ellenier, populated by Elvians. Just look at their King!.
- In a bonus level in Gex 3: Deep Cover Gecko, there's a poster of a Christmas elf resembling Elvis named Elfis.
- This Elf Only Inn strip, setting up for an elvish wedding.
Woot: Then, as the music reaches a climax, you and Lord Elf will walk down this path, which will be carpeted with rose petals, to be married before THE KING!!!
Megan: This is very lovely, Woot. Thank you. But just to be safe, when you say "the King", you're not talking about a Vegas-style Elvis impersonator, are you?
Woot: Uh, of course not.
Herman (dressed as Elvis): That's not what you told me.
Woot: Herman, I distinctly said "ELVISH" impersonator.
- This strip of Rusty and Co. has a character making a not-so-subtle jab at Roxy, the elf bard:
"Oh come now, my dear! Are you an Elvish performer, or merely an Elvish impersonator?"
- Larry's silly song in VeggieTales's Lord of the Rings parody had him dressed as Elvis (and emulating his style) while singing a song about being in love with a girl who speaks Elvish. The reaction from the Legolas parody? "You're not a real elf! You're an Elvish Impersonator!"
- Melfis, the leader of the Elves in the videogame of Faxanadu was in two episodes of Captain N: The Game Master. He shared some facial features (not to mention the wardrobe) of the singer, but with...blue skin.
- In the Christmas Episode of ChalkZone, the head Christmas Elf is a Elvis Presley lookalike.