Nicely done! Overall your work throughout this lesson was well done, and you've done a good job of employing many of the concepts from the lesson. You've demonstrated a strong grasp of the relationships between the forms you've combined and how they exist together in 3D space. There are a few issues I'm going to point out, but all in all you're headed in the right direction and are making some solid progress.

The first issue I wanted to touch upon was in regards to the use of additional masses. You've made efforts to apply them in a various places throughout these constructions, with varying levels of success. When it comes to these masses, the way in which their silhouettes are shaped is integral to how effectively they read as part of the construction. So, let's talk a bit about that.

The easiest way to think about these masses is to first remove them from the construction, and imagine them floating in the void. At this stage, they're just a ball of meat, in its simplest form, its silhouette made up only of outward curves. When we press this ball of meat against an existing structure, we start to develop complexity in its silhouette, along the sides that press against other solid entities. As shown here, this causes it to develop more inward curves and corners, each responding to specific aspects of that structure.

So the key here is twofold - firstly, complexity in the silhouette goes only where it makes contact with another structure. Otherwise the silhouette should remain simple, meaning outward curves. Secondly, where we do add complexity, it needs to be in direct response to forms whose position and nature we fully understand, rather than just arbitrary complexity added in the hopes that it'll read correctly. Here's what I mean.

The next point is a quick one I don't see coming up often, but in the rabbit on this page, you established a ball for the cranium, then cut back into its silhouette. As explained here, do not alter the silhouette of forms you've constructed. Always interact with them in 3D space - silhouettes themselves are just 2D shapes that represent forms, and by altering them, you break that relationship.

Continuing onto more general head construction, I'm noticing that you tend to treat the eye sockets more as though they're the visible part of the eye. This isn't quite correct - instead, they need to be larger, as they represent the actual socket cut into the skull itself. As this course is constantly evolving, I tend to develop new ways of explaining things while critiquing students - and while I intend to incorporate them into new lesson content (I'm currently starting a complete overhaul, slowly, from Lesson 1 onward focusing on video content), I of course share this information as it is available both in critiques and in the 'informal demos' page of the given lesson. Here you'll find a detailed explanation of how to think about head construction, and how the eye sockets serve as the first major point at which we start dividing the head structure into a series of more complex planes. Based on your current approach, it doesn't appear you've seen this, so be sure to give it a read.

Aside from those points, your work is coming along quite well. I'll happily go ahead and mark this lesson as complete, so keep up the good work.