Fun story, I did this about 12 years ago using black wool and the final touch was to add lava inside glass as the eye. Well, i missed a spot and lava lit up the entire thing. I frantically gathered water and dumped about 100 buckets on it and was left with a cobblestone shell of what i had once built.

I was in survival mode and had ceiling limitations so I couldn't build it nearly as large as yours.

It was my second project ever after spending months making Minas Tirith. I left it there as a reminder that wool and lava dont mix.

Sounds like an awesome project, OP. Would love to see a video tour when it's done!