I looked at the hole class with one Year experience in Thumpnailing and a decent knowledge about Creature Design beforehand! Yet take my stuff with a grain of salt since I’m only 18 and have yet lots to learn! 
i used the Brush provided to act as an extra challenge for me! 
Here are my Thumpnails ! First up using the Brush provided to get Ideas down with line, that did not work to well for me! Back up right with first Headshots. I wasn’t sure if I want to go in a Horror direction or a Fantasy one. I settled on a more classic one in the end! My main Idea was something with Wildlife you can find here in my Area! Wild boars as my Fokus More detailed sketches done under 5 min to get my Idea down! It’s here there I settled on the Thumpnail I liked the most and mixed new elements in! In this Stage I thought about Resident Evil or Dark Souls as Inspiration in my Head. I remember these games real good 

And back to the provided brush! In this I settled on most of the Detail accept the Meat Clob! That was a quick idea right at the End! I wish I had the Idea earlier hhh

I drew this along the hole class and had time to shade a liddle ^^ 

overall! All things I already knew to some extent, but really fun to look back to! The spine lesson really helped! I hope you guys like what I did!