Starting with your organic intersections, these are looking great. You're really nailing how those forms slump and sag over one another, and selling the impression of volume for each individual one. Your cast shadows are coming along nicely as well, maintaining a consistent light source and further reinforcing the curvature of these surfaces.

As a whole, looking at your animal constructions, I am quite pleased with your results. There are a few places where I think I can redirect your approach and help keep you on the right track as far as this course is concerned, but as a whole you're demonstrating a very strong understanding both of how these forms sit in three dimensional space, as well as how they relate to one another within it. You're combining them effectively to create complex structures that still appear solid and believable despite their own complexity.

Starting with your head constructions, I think for the most part you're showing a good grasp of how building a head is all about fitting these pieces together into a sort of three dimensional puzzle. You avoid having things floating more loosely from one another, and focus quite a bit on the relationships being established between the forms that fit against one another. I do think this can be pushed further however - the approach I explain here relies on larger eye socket shapes of a specific shape (an upturned pentagon), but it gives us key areas for other components to fit in, like a wedge between them to fit the muzzle, and a flat top across which the brow ridge can rest. This can help a lot in further pushing the solidity of that head structure.

Additionally, when drawing your eyes, you're doing pretty well at figuring out how to wrap those eyelids around the eye ball form, but this can be taken even further if we treat each individual lid as a separate additional form as shown here.

Speaking of additional masses, I noticed a few different approaches in your drawings. In some of them - for example on the top-left cat's rump on this page you're doing an excellent job of shaping the silhouette of that additional mass such that it wraps around the existing structures (including the hip mass), and generally avoiding complexity where nothing is pressing against it. This results in a very purposeful, intentional structure that enforces its own volume without the use of any additional contour lines. This is actually the main trend I'm seeing - for the most part you're doing this very well.

There are however some cases where the additional masses are less purposefully designed. The masses on the top-left dog's back on this page appear to be curving around non-existent structures, making them seem a little more vague and uncertain. While for most students I'd push them simply not to add complexity where other forms don't exist to provide that influence, in your case it's clear that you do feel that there is a form there - so the better solution would just be to actually add it as well. So for example, towards the dog's backside, there's clearly something causing an inward curve, so make sure you add the form that does so.

We can see similar issues with the bottom right rhino here, where the mass along its rump/backside has a very prominent inward curve along its bottom edge, but there's no logical reason for it. Here I definitely would have left that complexity out, and instead would have focused on just wrapping around the rhino's main torso.

I noticed that the head construction on that drawing felt a little uncertain, (and on the top rhino you also ended up with more 'floating' elements) so here's a demo I've got on how I'd tackle a rhino's head.

The last point I generally focus on is leg construction. In your animal constructions, you've employed the sausage method very effectively, though I did notice you strayed from it in your hybrid. Remember that these are all tools in your toolbelt - there's no reason that you need to tackle things any differently when the challenge itself changes. A leg is still a leg, after all.

So! As a whole, I'm very pleased with your work. I've pointed out a few things you can continue to work on to continue growing and improving, but as a whole you're doing very well. I'll go ahead and mark this lesson as complete.