I've given a name to tileset 3. I didn't manage to get my mushrooms added back in, but I think all the additions made are excellent.
Sorry about that. Maybe your mushrooms can be added to a future tileset. Maybe even this one!
Here's my contribution. I felt obligated to add bones as the author of the bone tilesets in Knytt Underground.
For future participants: The bone ends have übertransparent pixels so that Juni can climb them smoothly, but don't worry about preserving these, they can always be added back in at the end. Also, the outlines so far are very dark blue, not black! Wait... maybe I should have interpreted that as 'these aren't solid objects' and changed the colour palette for my bones...?
Edit: While contemplating the solidity of egomassive's tiles, I decided it would be cool to have the option of crawling all over them, so I made a second version of the tileset with an übertransparent tile for demonstrative purposes. Place the spinal column on layer 2, then overlay the invisible tile on layer 3 to see it in action! I'd be interested to hear everyone's thoughts on this.