You're right it's strange. While I can't find anything about the story they're in or the person who wrote it I've sent a message to the person who did the picture of Bärkatlànm (Szarëgg's father) who seems to know more about it than anyone else.
most of the info on the page came from wikipedia, but the page seems to have been erased now. I guess the source story is not well known and someone who fancied it decided to put it on there. (alternately it was a hoax that nobody caught)
I don't think the artist can help. When I tried to source the image used for Barkatlanm, I found the artist but his name for it was just "hammerhead alien". Truth be told I hesitate to erase the picture from the wiki outright, but maybe it was used on a mythos card game or something?
Probably should have done my homework, it seems that CoffeeForKafka's page is more of a compilation page with pictures from multiple sources that they've likened to Lovecraftian monsters (one of which they admit is a worm from Dune). Sorry for the confusion.
Edit: to redeem myself I did some digging in the file history and from what I can tell all of this stems from a Spanish Student of History called Sergio Roberto Sbeghen Campos. The first mention of either character's name was when 22.214.171.124 added Bärkatlànm to the bottom of the list of the Great Old Ones at 00:20, 25 August 2017. Two days later at 15:50, 27 August 2017SergioCamppo appeared, moving the name to its correct alphabetical position. Two and a half hours later at 18:09, 27 August 2017 he created the page Bärkatlànm. He listed several aliases, powers and family members (Including Szarëgg as Bärkatlànm's daughter and The Copycat From Algoa as his son) but it was left to 126.96.36.199 to add the Quote and the Description. This is likely to be him again but it seems odd that they'd log on and off mid way and the combined facts that The Copycat From Algoa was changed to a summon and he references playing Lovecraft RPGs on his instagram suggests that it could be him and a friend writing about a character they created for a game. Neither account made further edits and aside from grammatical corrections by other users the next and last major change came at 19:22, 20 October 2017 when ElioSoSavage changed the Expanded Mythos sigil to the image of the Hammerhead alien created by David Kaye. Though a the caption for his painting of Great Old Ones on insta states "Which god do you worship? My faith is in Bärkatlànm." the image doesn't contain Bärkatlànm.
The Szarëgg page was made on the 12th December that year, it was 188.8.131.52's only edit and read "This is the article of all articles consisting of literally nothing." probably just because they saw the broken link on Bärkatlànm's page.
All this being the case I reckon the pages and picture should be deleted under the policy of not endorsing unpublished fan fiction but that being said I'll also try to preserve what I can here on the forums.
I'll put them on the "candidate for deletion" for a while, in case something else comes up (though i doubt so)
I'll have to check some other images, I know some of them are not originally made about the article. (i'm not against using fan drawing, heck even wikipedia does it, and it's been a long part of this wiki policy before i came aboard but i'd prefer them to be about the original subject)
Oh yeah, I've got nothing against fan drawn art as the wiki needs a little more colour and the only "canon" art Lovecraft did himself is a pales in comparison to his writing (to be honest when I still thought they were the OP I considered asking CoffeeforKaffe if we could use more of thier stuff). I was more refering to the text and only included the picture as it was never intended to have anything to do with Lovecraft.