What’s the first thing that comes to my mind when the name of John Howe shows up? The Lord of the Rings! Peter Jackson liked so much the work of this artist surrounding the Middle Earth that he hired him to be one of the lead designers for both his trilogies of TLOTR and The Hobbit.
He has got a huge amount of beautiful work in traditional media mainly in the fantasy realms, from book covers to posters, depicting a lot of mythological stories and creatures.
You should definitely check out his book “Fantasy art workshop” if you are interested in illustration, in which he explains a bit his process on how he created some of his pieces of work.