Howard Lyon is the artist of this piece, I have contacted Wizards of the Coast and they are waiting for me to send them the link to this page, as well as your deviantpage. If this is not taken down within the next 48 hours, they will be notified promptly. DeviantArt admin will follow accordingly.
I have to recommend against posting the works of others without the permission of, and proper credits to, the author. I am disinclined to believe that you were able to acquire permission from WotC artists, and even if this is a derivative work, it is still considered proper artistic etiquette to credit the creator of the source work. Please update the description with either credits to the artist of the source, or of this work it's self, and I will forgo reporting the work to dA