With these sketches, I was trying to discern what male/female variants of the creature would look like, as well as how their foliage should look. At the moment, I'm liking the look of branches protruding from some of their joints (especially around the torso) and their heads.

I'll continue trying out different shapes of leaves for their foliage but think that keeping everything small and spindly looks the best, at least for smaller creatures. Perhaps larger leaves would look better on the quadruped?

I'm liking the look of 1 and 13, so I'll most likely recreate those designs in Photoshop and make some variations of them, and make them look a little more rigid and skinny, as well as slightly alter the overall pose of 13, especially the arms. On top of exploring more in terms of overall design, I want to experiment more with their faces, as I think it would be interesting if they wore some kind of masks or decorated themselves in some way, perhaps actually carving their faces into the shape of masks as they're made of wood.