Overall, nice work! There are some issues, but as a whole, I'm used to looking for certain key issues and you're well past the big ones. It's just a matter of of drilling down into some deeper concepts, and based on what I see here, you are well equipped to handle them

Starting with your organic intersections, these are really well done. They strongly convey the illusion of form and volume, and establish the interactions between the forms in an entirely believable manner.

Moving onto your animal constructions, I'm mostly going to focus on the major issues I'm seeing, but as a whole I think you've made excellent progress in developing your constructions with a strong respect for 3D space and for the forms that make up each structure.

So, onto the issues:

Follow every step of the sausage method

This is a short one. You're mostly doing a good job of using the sausage method, but you're missing a very important part - defining the intersection between the sausage segments with a contour line right at the joint where they meet, as shown in the middle of the sausage method diagram. This is more than just important in this technique, but rather defining the relationships between any two forms that touch is quite critical to help develop a strong impression of three dimensional structure. Another big way in which this is used is the connection between the neck and the torso, where you're doing a better job of using it consistently.

The use of additional masses

Every additional mass can be thought of as a ball of soft meat floating in the void, which we press against our construction to help give it additional volume/bulk where it's needed. It won't merge into the other forms - not the existing basic structure, and not with the other additional masses. Each mass will remain independent, existing on its own, but clearly interacting with the other elements of the construction.

So, this manner of thinking about the additional masses as balls of soft meat comes into play in two different ways.

First, it's important that as explained in this diagram, we focus each such mass on performing a single job. If you try and have it do too much, you just end up with too complex a shape, and it fails to really feel believably three dimensional. For example, take a look at the long, continuous mass on this goat's back.

Secondly, the ball's natural state is to have outward curves, in order to maintain the simplest of possible silhouettes. Complexity is introduced to its silhouette only when the form is pressed against some other structure - and as is often the case with working in 3D space, we have to be aware of the nature of these other forms, alongside the mass itself. To put it simply, you can't be adding complex corners and inward curves without knowing and defining what they're pressing against. This diagram will help you think about that.

Every inward curve and every corner must have a culprit. So, looking at the same goat's back, there's a wavy pattern to that edge, where it curves inward, then outward, then inward again, etc. but there's nothing there to actually push down upon it.

Similarly, if we look at the masses you add to your animals' legs, you're attaching them along the outside, but not actually thinking about the kinds of forms they'd be pushing up against on the interior of the leg's silhouette. If you remember the dog leg demo and the ant leg demo I shared in my critique of your lesson 4 work, I don't just concern myself with what's going to impact the silhouette. It all ends up working together.

Similarly, minding forms along the body like the big shoulder and hip masses of this bison helps a lot in determining how to build up those back masses.

Head construction, and the importance of the eye socket

The last thing I want to call out comes down to head construction. This is one of many parts of the lesson I plan on updating (basically I learn more about how to convey the information by giving critiques, and then I provide students with that information through the critiques, and eventually determine how to incorporate that same information into the lessons themselves), but I have recently put together a more thorough explanation of how to think about head construction in this informal demo. Look at the demonstration itself and read through the explanation in the text.

At its core, it's all about how important the eye sockets are, and that is largely missing from your drawings at the moment. The eye sockets should be drawn bigger, and everything else - the muzzle, the cheekbone, the brow ridge, etc. should all be forms buttressing against the eye socket, all fitting together like a 3D puzzle. Furthermore, the eye socket's role as being the first step in taking these smooth surfaces and breaking them down into a series of planes is important.

So! I'm going to assign a few additional pages on which you can demonstrate your grasp of the explanations above. You'll find them assigned below.