Day 18 is: MASK and Day 19 is: CREATURE FROM THE BLACK LAGOON
Day 18 is pretty wide open, but knowing that I was going to have to combine it with Day 19, which is pretty darn specific, I chose to make another switcheroo and have Ariel, Disney’s Little Mermaid with a Creature mask on 18 and the Creature with an Ariel mask the next day.
Inked and colored pencil on day 18 and inked and scanned it to color digitally on the 19th: