Ice-shroom

freezes all zombies when it wakes up.

Plants Vs. Zombies: The Next Levels
Ice-shroom is unlocked much later than in the first game, being unlocked in the Ice Caves.

Suburban Almanac
Main article: Suburban Almanac (Next Levels)

"Ugh, Summer..." Ice-shroom says with disapproval, "I frown upon you, just like I frown upon everyone because of my freaking facial nerves being paralyzed."

Plants vs. Zombies:The Fall of The World
Ice-shroom randomly appears in Conveyor Belt levels.

Almanac: ... He doesn't talk. Because he is melting.