File:FelFire Ragnaros Alex Horley.jpg

Summary
A green Ragnaros in the HS Felfire Festival event.

Source
http://wow.blizzgame.ru/assets/Warcraft-Gallery/FellFire-Ragnaros-by-Alex-Horley.jpg

Shown in the following trailer:
 * Hearthstone Felfire Festival | Seasonal Event Trailer

Different version: http://www.alexhorleyart.com/comics/court_dead/FellFire1.jpg
 * http://www.alexhorleyart.com/wowtca_hearthstone.html