On the server MCMagic, I found a head inside a glass block at the Japan pavilion (
/warp japan) in Epcot. Because this was the first time I have come across that, I have no idea how it was done.
In singleplayer, I tried using a piston to shove a head inside a glass block, but the head kept dropping itself. Then, I tried placing more glass blocks around the first one to prevent the head from popping out, but it still did after I activated the piston. How do I keep a head inside a glass block?