I'm just gonna say that Pokemon in its own way have a weird anatomy in general. As of the drawing, I must admit that it reminds me of a weasel on the head, but the bottom portion reminding of an dog attempting to stand -and they don't really stand for a very long time lol-
However, I'm just gonna say that your characters have that 'human' style is because all of them are walking on twos xD I tend to also think that the moves passing down to a child, doesn't give any physical additions such as claws, rather I think Slash is supposedly for the tail -- considering that it's about like, motor boat power. Nonetheless, Pokemon do have a weird way of stuff ^^;
Concerning Buizel anatomy, it actually depends on the mood of you character; your drawing is a bit different from it, especially on the lower half. Compare yours with the official Buizel artwork [And compare it with a real life weasel], at the hind legs where the Tibia and Fibula bone meet the Femur, is different among the comparisons. In this weasel picture, however, the hind legs are as of a dog's when sitting, this is when they're relaxed of course. As I said earlier concerning the mood, what are they really acting like? Are they relaxed? Cautious? Anatomy does not differ in these parts, it's always of body language does it tell the story.
Just like in the picture earlier, if they're relaxed, they would be sitting like a dog. If cautious, they would probably have their head trying to face the direction where most area would need to be covered, or them attempting to stand - for a short amount of time - to check if the coast is clear.
Sorry if I don't make sense or anything :U I'm kinda derping today lol, but this is what I could manage for the moment.