Called on every one of your skull blocks placed in the world
It have 5 arguments, as listed below:
(number) - the tick delta
(blockstate) - the block, when rendered from a block
(itemstack) - the item, when rendered from an item
(entity) - the entity, when rendered from an entity
(string) - the type of the rendering (LEFT_HAND, HEAD, BLOCK, …)
If the return value is true, the skull will not render