Jumping right in with your organic intersections, by and large these are really well done. They demonstrate a (mostly) realistic arrangement of forms that abide by the laws of gravity and establish strong spatial relationships between them. I say mostly because of this one which definitely would have sagged more under its own weight, but that's really just nitpicking.

Continuing onto your animal constructions, as a whole I think you've done a great job. You are certainly correct - the demos that are there are quite outdated and scattered, and while I'm desperate to update them right this minute, I'm instead steadily moving through overhauling the entire course from Lesson 0 onwards, and I keep running into pitfalls and delays that are simply unavoidable. The informal demos are pretty much my bandaid solution to this, but obviously they are not as good as a proper demo integrated into the course material.

I think it makes the most sense to look at your animal constructions under a few different topics, although fortunately most of these will be short, as you really have done an excellent job here.

General Construction

Here I really don't have much in the way of complaints - just a couple minor things. For example, you appear to be drawing your initial masses (like the cranial ball, the ribcage, the pelvis) more faintly than the rest. While you're still treating them as being fairly solid, and avoiding cutting back into their silhouettes in ways that would flatten them out, drawing them so faintly is really just asking to slip up and ignore their presence as solid forms. Instead, draw every mark - including the early ones - with the same confidence and line thickness as any other. It is worth mentioning that right at the end of the set, you do a better job of this.

Use of Additional Masses

So this is an interesting case, because you've got a ton of spots where you're leveraging them extremely well, and some cases where you're dropping the ball a little. On your animals' legs, you're designing their silhouttes in a very purposeful manner that creates a strong relationship between each of these masses and the existing structure they're wrapping around. This silhouette design is a lot weaker however when adding forms to the animals' torsos.

While it's clear to me you understand this on some level, it may help to say it anyway - one thing that helps with the shape here is to think about how the mass would behave when existing first in the void of empty space, on its own. It all comes down to the silhouette of the mass - here, with nothing else to touch it, our mass would exist like a soft ball of meat or clay, made up only of outward curves. A simple circle for a silhouette.

Then, as it presses against an existing structure, the silhouette starts to get more complex. It forms inward curves wherever it makes contact, responding directly to the forms that are present. The silhouette is never random, of course - always changing in response to clear, defined structure. You can see this demonstrated in this diagram.

We can see this in action here on your armadillo lizard - note how each inward curve is positioned very specifically in order to establish how they're wrapping around existing structures. To that point, I also blocked in the muscle groups right at the shoulder and hip that are always present on quadrupeds as simple ball masses, so that the masses I did add could wrap around them, giving us a greater sense of grounding.

To that point, I should mention that you can get an even stronger sense of structure when building up masses along the legs if you don't only focus on the ones that impact the legs' silhouettes. You can see this demonstrated on the back leg of this dog from another student.

Leg Construction

Here you've done a great job, and I have no complaints (aside from the one I mentioned at the end of the last section). You're making good use of the sausage method, you're building up additional masses with consideration to their silhouettes. All looking good.

Head Construction

Lesson 5 has a lot of different strategies for constructing heads, between the various demos. Given how the course has developed, and how I'm finding new, more effective ways for students to tackle certain problems. So not all the approaches shown are equal, but they do have their uses - which is why, as you noted, some of those outdated ones are still present. As it stands, as explained at the top of the tiger demo page (here), the current approach that is the most generally useful, as well as the most meaningful in terms of these drawings all being exercises in spatial reasoning, is what you'll find here on the informal demos page.

There are a few key points to this approach:

• The specific shape of the eyesockets - the specific pentagonal shape allows for a nice wedge in which the muzzle can fit in between the sockets, as well as a flat edge across which we can lay the forehead area.

• This approach focuses heavily on everything fitting together - no arbitrary gaps or floating elements. This allows us to ensure all of the different pieces feel grounded against one another, like a three dimensional puzzle.

• We have to be mindful of how the marks we make are cuts along the curving surface of the cranial ball - working in individual strokes like this (rather than, say, drawing the eyesocket with an ellipse) helps a lot in reinforcing this idea of engaging with a 3D structure.

Try your best to employ this method when doing constructional drawing exercises using animals in the future, as closely as you can. Sometimes it seems like it's not a good fit for certain heads, but with a bit of finagling it can still apply pretty well. To demonstrate this for another student, I found the most banana-headed rhinoceros I could, and threw together this demo.

So! As a whole, you've done a great job. I've offered you a few ways in which you can continue to push forward, but you are definitely good to consider this lesson complete.