Poster Art Question

Does anyone know who painted the artwork used on the European posters for this film?

I'm sure it's not Jeff Jones, who did the US poster art; the style's completely different. Speaking of Jeff, while he is otherwise a superb artist, the effort turned in for the US poster is pretty atrocious – what went wrong?!

Anyhoo, the image I'm referring to has Vermithrax crawling across a lake of fire towards the hero & heroine in the foreground with, in most cases, Ulrich appearing as a ghostly figure above the dragon.
It's employed to greatest effect on the UK quad, but other versions can be seen in IMDb's poster section for this film, as well as elsewhere on the web.

I've got the original UK quad & poster mag, the US Movie Special mag, pressbook & Marvel Comics adaptations & none of these list him/her anywhere...

I've been searching for an answer to this question since the film first came out (I literally lost count how many times my brother & I saw it at the cinema!)... you guys are my last hope!