Experiment with Japanese watercolor, Dr. Ph Martin watercolor and India ink/pen.
The creature was primarily done in this Japanese watercolor that is called something like shadow set. The colors are black with a tint of color which creates a subdued hue depending on the ratio of water used. The Dr Ph Martin watercolor is super pigmented to create some vibrant hues even when diluting with water.
Using color was an interesting challenge. The limited pallet was on purpose. I did this on heavy weight paper, it worked out well even when I dumped watercolor on it to excess.
I like the contrast between the watercolor and also the idea that this abomination is out in broad daylight rather than waiting for night. I think it makes it more terrifying and bizarre.