using /summon ~ ~ ~
with some block ids like water, doors, saplings to not render or render weird.
Blocks with flat textures held by player in third person view, villager / iron golem or enderman have z-fighting
Thin black stripes over mooshrooms / iron golems / enderman / falling block with mipmapping
Some blocks are invisible in enderman's hands
Stained glass held by an enderman is opaque
End Portal Block not rendered when enderman hold it!