Not Enough Wands

1.5.2:

• The swapping wand can now no longer swap in blacklisted blocks as well (i.e. you cannot select a blacklisted block in addition to not being able to swap out a blacklisted block)
• There is now also a blacklist for entities. The ender dragon is blacklisted by default and the wither is configured to be twice as expensive.On 1.11 you should use 'minecraft:chicken' notation to blacklist a mob. On 1.10 you should use the old entity name which is 'Chicken' in this case.