Starting with your organic intersections, these are by and large being done fairly well. You're mindful of how each form slumps and sags over its neighbours under the force of gravity, and you're doing a good job of handling the cast shadows in a consistent manner, with consideration for how the surfaces they fall upon deform through space.

Moving onto your animal constructions, for the most part you've done a bang up job. There are a few things I'll want to call out to keep you on the right track, but I can see that you're making a great deal of effort to apply the principles from the lesson as closely as you can, with a particular focus on building things up with individual, solid, 3D forms - rather than viewing the additions as flat shapes or individual marks on the flat page. I can see this improving throughout the set as well - where earlier on with these birds you ended up cutting into the silhouette of the initial head mass slightly (remember that when you end up with a looser ellipse, treat its outermost perimeter as being the silhouette's edge), I didn't really see this issue come up too much further into your set.

Looking at how you approached building your legs, I can see that you were making a conscious effort to apply the sausage method, and in many cases you did so successfully. There are however some areas where you veered towards using stretched ellipses/ball forms rather than sticking to sausages - for examples, we can see this in the back legs of this elephant. Just something to keep in mind.

Another point to call out has to do with how you approach designing some of your additional masses' silhouettes - specifically, the use of corners. On this gorilla I pointed out a number of sharp corners with red arrows - specifically ones that occur somewhat arbitrarily. All complexity in these silhouette designs must occur only in response to existing structures. In green I pointed out one such sharp corner that is caused where the mass presses against the cheek masses of the head, so that works fine. I also drew one along the backside, where we use an S curve where a sharp corner can't be used, and then a sharp corner where the mass presses up against the leg/hip area.

Hips and shoulders are particularly useful for this, because most animals - especially those who walk on all fours - will have more muscles built up here. It's not always really obvious, but if you know to look for it, you'll be able to see it in your references, and this will give way to chances to add simple ball masses at these locations, then wrap existing masses around them, creating a more integrated "3D puzzle" kind of appearance which really reinforces the sense of solidity.

Continuing on, one fairly minor concern is that I do see you throwing contour lines around a bit freely (and without too much thought to how they're being executed, or what their purpose is meant to be). For example, we see some in various places on this horse - along the front of the throat, on the upper section ofthe back legs, etc. Every mark you put down, and every tool you employ, must be used with an awareness of what its purpose is meant to be. That's what the ghosting method's planning phase is for - ensuring that we understand what we're trying to do, and to spend a bit of time considering whether our instinctual choice is really the best one.

When it comes to these kinds of contour lines - those that sit on the surface of a single form - it's great for teaching the concept of a contour line, but they actually aren't useful that often in practice, since they suffer from diminishing returns. Piling on a ton won't make your form much more solid than just one, but when we lean more on quantity we tend to spend less time on the execution of each individual one, giving us a sloppier result.

The last thing I wanted to suggest is that when you draw feet, always be mindful of the fact that those feet are 3D objects - the best way to remind ourselves of that is to actually draw them such that they feature distinct planes. This is one area where we can actually use corners in our additional masses more effectively, as shown here - although the reason here is that the foot is pressing against the ground. Such corners can imply the separation of planes. Thinking "boxy" for any kind of feet is usually beneficial - and we can also build upon such boxes with further boxy forms to add toes when they're necessary, as shown the notes I drew on another student's work.

Now, all in all your work really is coming along well - you've especially shown that with your horses, which capture both a strong sense of solidity as well as a clear sense of motion and gesture. So, I'll leave you to keep these points in mind and apply them in your own practice. You may consider this lesson complete.