With Resist +1, Kronk, Junior Chipmunk takes one less damage when challenged by an opposing character, giving his five willpower even more durability
Of course, these all work wonders with those Bishop of Wings effects
A spell or token with changeling is just as much an Elf, a Dwarf, a Sliver, a Goat, a Coward, and a Zombie as it is a Shapeshifter
Since it only prevents damage during combat, you can easily drop it with a Ghitu Slinger, Murderous Redcap, Lightning Bolt, or Flametongue Kavu, and that's in addition to stuff like Shriekmaw, Nekrataal, or other fun removal-based cards
This can only be done during your turn
This is a no-brainer, but theres just no best booster to buy because it all depends on your need