So your work here is basically about as good as it could be. It's not perfect, but it's extremely close to it (as far as this course goes), and you should be proud of what you've achieved. I'm going to call out a few minor issues that come up here and there, and are worth talking about, but as a whole you've definitely knocked this one out of the park.

I've called out a few points on this page, but let's take a look at them one by one.

• On your bottom-right bird, I caught a big chunk of the original cranial sphere that you cut off from your construction. It's important that you treat every form you add to your construction as being solid. This means refraining from altering those forms' silhouettes once they've been drawn. As shown here, doing so will break the relationship between the 2D shape on the page, and the 3D form it is meant to represent. While there are ways to cut back into our 3D forms properly without breaking the illusion, it doesn't work particularly well for organic subject matter. So when drawing animals, it's best to always work additively, building on top of what we've built out. If we end up going too big too early, then ultimately we have to accept that - there are certain things we can't change or alter in order to make them replicate the reference image more accurately, and that's fine. our focus here is less on recreating the reference image, and more on using the information within the reference to create something believable and solid.

• When it comes to those additional masses, the silhouette of those forms is incredibly important to believably integrate it into the existing structure. Now for the most part you've done an excellent job with this, but one thing to keep in mind is that all the complexity in the silhouette occurs in direct response to contact with another form. When the mass exists on its own, floating as a ball of meat in the void, it's going to be in its simplest state, made up only of outward curves. When it presses up against something else, it'll develop inward curves, and corners, increasing the complexity of that silhouette as shown here. As such, whenever we see inward curves in the silhouette, it should be because something is pressing on it. If there is nothing pressing upon it - like along the outer edges of these masses - we need to stick to simple outward curves. We can of course layer more forms together to create little dips and divets, but if we try to accomplish this with a single mass, it will make that mass appear complex without a logical reason for it, which in turn will make it appear more like a flat shape.

• For head construction, you're generally doing just fine, but I do think that it might help to just focus a little more on the simplified core structure. Right now you do delve into more complexity and I feel that could potentially obfuscate the underlying structure in a way that can get in the way of what we're really learning and practicing here. Take a look at this breakdown of how to think about head construction. I'm sure you understand it already, but take a look just to be sure.

Aside from that, your work is extremely well done. I'll go ahead and mark this lesson as complete, so keep up the good work.