Normally, using Pick Block (defaults to Button 3, the scroll button between left and right click) on a block gives you the block, and doing it on an entity, let's say, a zombie, will give us Spawn Zombie. This functions properly , but there are some other oddities:
Let's say go up to a chest and Pick Block it. This will give us Chest: no contents. Let's say we, instead, press Ctrl+Pick Block on a chest. This gives us the chest, the contents of the chest and it says +NBT below Chest.
Finally, attempting to Ctrl+Pick Block on a special entity, let's say, a husk, gives us a blank Spawn Zombie (same as before). And yet, it is possible to get a husk spawner:
/give @p spawn_egg 1 0 {EntityTag:{id:"Zombie",ZombieType:6b}} This feature will give a random husk spawner, as a baby will occasionally appear.
The attached pictures demonstrate this.