Alchemist's Cave
The best part about glowing green goop is that it's just begging to go somewhere and cause some kind of mayhem. If a crazed alchemist is using it to create monsters, and said monsters escape underground? Why, it would be irresponsible of me not to draw that!
This one was a pain to get illustrated because the gosh-danged shadows drove me up the wall for two hours until I finally figured out how to get them right - and it turns out, it was much easier than I was trying to make it. Isn't it always?