This is a mix of the 30MF Skeleton and the HG Zaku. I just put the head on, though. 💧
The Skeleton comes in a two-pack, which is great value and high quality! You can even recreate a skeleton swordsman from a movie from decades ago just by adding weapons! (*´ｪ`*) I debated whether to paint it like bone or make it look like a fossil, and ultimately decided on the fossil look. But it's still a mecha, you know (；´∀｀)
And I even showed it off at the Linkle Planet fan meeting the other day!

30MS Zaku | コベ's Gunpla works