I had a debate with myself about whether I could use other tools, but Olivia only mentioned body parts so I was a good girl :) I thought it would be relatively easy to do, but given that I use half pan watercolours, it is not that easy to find a body part to fit apart from a finger and I did not want to cheat by using a brush to get the colour out - it was all or nothing.
Attempt 1: immerse the paper and then mix up a nice dark of perylene green and perylene maroon.
Attempt 2: Dry paper, no sketch, black watercolour, right forefinger. Happy, but with black paint under nail.
I will eventually get around to finishing it off with some grass for the poor thing to eat and to explain the lack of hooves.