Sonic 3 Knuckles Artwork

The UK magazine 'Sega Xs' issue 6, 1993 featured a weird artwork of Knuckles. The magazine contains walkthrough and tips for Sonic 3. This either could be a concept art of Knuckles hence some people refer to it as 'Prototype Knuckles' or it was made just for the magazine article.

The page from the magazine:

Full magazine:

https://www.mediafire.com/file/ukduu6u0noasg2c/SegaXS_UK_06.pdf/file