Max out your XP Multiplier on the quest board.

Reach the boss wave using the Flag of Power in the Backyard Battleground.

Complete 'Captain Smasher's Curse'.

Complete 'Showdown'.

As the Chomper, swallow a Goat.

Enter Infinity as a Zombie.

Complete 'Strong Coffee'.

As Super Brainz, vanquish 25 Plants with Heroic Fists, and 25 Plants with the Heroic Beam.

Complete 'The Bean Situation'.

In solo ops, swap to another character.

Complete 'Yuck!'.

Enter the Plant Stats room as a Zombie.

Vanquish an opponent using a Potted Plant or Zombot Turret.