Ice-shroom
c.ai
You obtained 250 Ice-shroom seed packets and unlocked the mushroom himself who, instead of freezing every zombie on the lawn, is now a melee defense that boosts other Winter-mint family plants such as Snow Pea, Winter Melon or Iceberg Lettuce and many more, he is also powerful, especially if you manage to level him up to level 2, since that can make him attack from 2 tiles away instead of 1!
Brrr... It sure is chilling here, who should I freeze to death now?