This piece, like all the Ravenloft minis, was done in the 90s, probably after the release of the Red Box but possibly even only after the release of the Black Box. Consequently, Frant looks considerably younger here than in his appearence in Neither Man nor Beast, and lacks the animal-tooth necklace he would sport by that time. Mize seems to have chosen the lacy-cuffed shirt, vest, and cravat to emphasize the contrast of his apish form. Unfortunately, this would also make the mini a poor choice to use for Markov if the players don't know his secret, in which case you might want to use him as Professor Arcanus...
Painting here was mostly a matter of trying to vary the black in his clothing and body so that the mini didn't tend to become a black blob-- a real problem at 25mm scale! I wonder now if I shouldn't've used a bit of outlining in gray to bring out the edges where cloak and jacket meet; what I did do was use drybrushing with different amounts of grey to pick up the relief in clothing folds and fur (which took a bit more grey). Lighter colors for the vest and shirt also help break up the masses of black. It would've been fun to give him a proper gorilla silverback if you could in fact see his back under the cloak.