Good job getting through the homework. Your drawings are starting to feel solid, but there are some fundamental problems you can fix that can push the believability of your drawing further.

On your Organic Intersections, the biggest issue I see is that you're not keeping your forms simple. https://drawabox.com/lesson/2/9/complicated Your sausages should be simple, ideally with one curve. Longer, complicated forms are very difficult to keep consistent and you break the illusion of 3d.

You also seem to be having trouble with your line weights and cast shadows. When applying line weight, remember to use only one, continuous, overlaid stroke. You should ghost your stroke the same as if you were drawing anything else. You may miss your mark, but I promise that overlapping and off lines are better than "petting" your lines. For the cast shadows, I thought it would be best to do a paint-over https://i.imgur.com/Y6UQJf3.png. Remember that your forms cast shadows on other forms too, not just the ground.

Finally, on to your animals. I can see the forms in your animals that you're creating but you're having a lot of trouble with proportions. Those troubles are directly related to how you've interpreted the lesson. Above all, you need to work on your line confidence. There are many ellipses and lines that you've gone over 5+ times in these drawings. Drawn over lines are ambiguous, and when constructing will make your drawings weaker and less believable. Shaky lines, like in this dog https://i.imgur.com/g17GXUV.jpg, are against the lessons taught here. Even the marks on the tufts of fur need to have a clear direction.

The cranial ball that you start with (the ball at the end of the neck) does not need to encompass the entire head of the animal. You can add mass to it as you see fit, and you'll often get better results if you do not try to get it right the first time. Try not to think of the neck as a stiff cylinder, but as a sausage form or a branch that fits into a ball. The neck can curve in all animals. Draw a slightly smaller neck, with a smaller ball, and then add as needed. Feel your own head, and how your neck fits into it. Your face is almost like a mask that goes over the ball at the back of your head. This is kind of what the Loomis method for drawing heads is based off of, and can apply to all animals. Also, it's important that everything you draw reads as 3d. The muzzle on many of your animals don't have any construction. You need to do it every time.

My last bit of advice has to do with texture. You seem to be focusing a lot on adding texture to your drawings, but in a lot of instances it ends up visually confusing. You don't need to draw every tuft of fur, or every scale on a lizard. You don't really even need to draw in the stripped patterns of fur on a cat or a dog. You can imply a lot of information by adding just a few tufts of fur, or only adding scales in areas where it's dark or the form turns. It saves you time and it will make your drawings read better.

I know that's a lot of feedback but I honestly think it's great that you completed the lesson. I can tell that you're starting to think in 3d but if you begin trying to fix the fundamental problems you'll be able to work out the proportions easy. If you haven't already completed the previous lessons you really should do so, at the very least go through lesson 1 and 2. I'm going to recommend some exercises. It may seem like a bit much but I feel like it will help you out a lot if you intend to complete the next lesson.