(NOTE: Please do take some of my info about his canon origins with a pinch of salt? This is what i can gather from all my research, as I'm literally Argentine, and I don't know a lick of Korean, so this is all personal understanding, I'm just guessing for the most part.)

Eol (에올) originates from the old and obscure Korean game developer Family Production's "Eol's Adventure" and its point and click sequel "Adventure Of Eol In The Fantastic Island". he's the protagonist of both games and a mascot-platformer type character, 
as for his appearance? he's a fluffy critter with yellow fur, spiky hair and a very big puffy tail, his body is pretty anthropomorphic and he's very short, his feet are pretty much alot like the ones rabbits have. in the sequel for some reason, his more cat like arms are replaced with more humanoid arms. his design can be a little incosistent tho depending on official art as well as ingame, though some ideas of his design are consistent, it doesn't seem like he's any particular species, as far as i could know it seems made up for his franchise... 
He's overall a very peppy happy go lucky person, he's not usually defensive, unless there's a bad guy in his way, he's also even caring of others, his voice is very soothing!
he can use his tail to cling onto objects and even throw magic projectiles with them, he can slide, jump, the works!

he also has a darker-and-evil doppelganger counterpart, whose name is Careol. by the sequel the two have pretty much made up yet im not sure if they're on equal foot, since he doesn't sound that happy to see him when the two reunite...

Eol himself doesn't have a backstory per se, but i can atleast add on summary of the plots from the two games he's from as for some more background, these are revised from rough english translations from the old family production website! i just tweaked wording and added missing points here and there..:

Eol's Adventure (Released in 1995 on MS-DOS):
one day, some strange light fell to the beautiful island where Eol lived. Then with violent movement, the earth broke into two pieces and bad air was spread over the world. Almost all of the flowers and animals were dead and the darkness fell over this peaceful island. Under this situation, Eol decided to find the reason and he found it quickly. turns out It was a wicked wizard the one who was causing everything, his name was Careol. As our expectation, could eol beat him off?, he did!, he succeeded and beat him off, restoring peace to the island. 

Adventure Of Eol In The Fantastic Island (Released in 1998 on Windows) (note, no clear scan of the cover art exists, so this photo will have to do):
years later, Careol, who repented of his wickedness broke the crystal gem which has been keeping the balance of the world when he was cleaning the shrine of balance. For this reason, the world was almost ruined once again and the darkness covered the sky. Careol ran away and Eol started to find several scattered crystal gems for returning the world to normal, alongside that in his journey, he met some friends and faced challenges as well, such friends include a ladybird named Fri who helped him travel across several islands, all to retrieve the pieces of the gem, in the end, Eol succeeded once again, having a nice party at the shrine after saving the fantastic islands.

good thought sport!, my iteration of him follows years after the events of the first two games, in my design hes now even more humanoid, yet hes back to having paws like in the original, he's also the height of my sona, a little more heavy, also like my sona, and he wears clothing, because of course he does, mainly a red sweater inspired by the old family production logo, AND brown pants.

his personality is still pretty much what i think he acts like. in my headcanon he's also more of a gentle person, a little naive and he doesn't go on adventures as much as he used to, since he wants a break from it all, which understandable!

as a result, hes gotten into other hobbies, like gardening! picking berries and..as a shared interest with my sona, whom he got teached by as to what it entails, tech and gaming!

i imagine hes also got cat-like and dog-like traits, as i imagine him purring and wagging his tail at times..

to me, i mean, why would'nt i?, he's so fluffy, cute, energetic and adorable!, it honestly to god irks me he's lesser known and the most of attention he got was a bad vinesauce stream where he was treated like a fucking joke. his games are good! the controls of the dos one can take some learning to but that aside, i love the ost! the pixelart is cute! why be so mean about him????, but besides, there might be some heavy language barrier to me, since i am Argentine, yet still, i just can't help but stim everytime i think about him, he just fills me with joy! it can get a bit overwhelming at times though...

(C)2026 MisaeRockabout!.
Eol belongs to Family Production. This is a non-profit fanpage made as a labor of adoration by a selfshipper.