'The Wolf and the Fox' is not one of the best known Brothers Grimm tales and in my mind it should be better known. Both the titular characters are interesting (with the former being a bully and one you don't like much at all and the latter being one that one can't help rooting for and understand their actions), with a relationship dynamic that sees their personalities contrasting very well. The ending is disturbing but the disturbing factor is not uncommon with Brothers Grimm.
'Grimm Masterpiece Theater' (or 'Grimm's Fairy Tale Classics' to others) does a very nice job with adapting the story. There are a lot of differences, though they are not ones that harm the story (the wolf's terrible hunting skills actually made me even more interesting) but a fair share of recognisable elements too, even though the original story's ending is not completely maintained the ending here is far from happy or pat really. The series' version of 'The Wolf and the Fox' does very well in making the story accessible for whole families while not dumbing down its spirit with the likes of over-sentimentality, juvenile humour or the like.
Most of the animation is nice, some beautiful use of colour and rich attention to background detail. The intro and outro theme songs are charming and the music isn't too jaunty or too much of a drone, even though it doesn't always fit in placement. The writing is not too simplistic nor is it too convoluted while the story doesn't feel rushed or padded. The ending has the right amount of unsettlement while not being traumatising.
It also nails the chemistry between the wolf and the fox, which has the right amount of tension. The wolf is even more of a bully than in the original story and one doesn't feel sorry for him one little bit, this is not a flaw though because that's the case in the original story as well. As is the characterisation of the fox, while not condoning his actions it is hard to not be on his side and understand why he did what he did (having had enough of his mistreatment and being ignored, it is enough to make anybody crack). The voice work is not bad, with the narrator faring best, then again always did love how the series was narrated. That for both the wolf and the fox fit their personality traits well.
Not all the animation is perfect though, the drawing being less than smooth and looking rather rushed.
Although the voice acting wasn't much of a problem, the synchronisation between it and mouth movements is often poor because of it very rarely matching properly.
Summarising, very nicely done. 8/10