Ice-shroom


 * For the version in Plants vs. Zombies: Garden Warfare, see Ice-shroom (PvZ: GW). For the plant in the Chinese version of Plants vs. Zombies 2 with a similar name, see Freeze Mushroom.

Ice-shroom is a mushroom that is treated as an instant-use mushroom. When planted, it freezes every zombie on screen for 5.5 seconds and also deal one normal damage shot. Once unfrozen, the zombies will still be slowed down, as it was hit by a frozen pea or frozen melon. It is unlocked after Level 2-7, and it is the 15th plant the player unlocks while going through their progression in Adventure Mode.

Suburban Almanac entry
Ice-shroom

Ice-shrooms temporarily immobilize all zombies on the screen.

Damage: very light, immobilizes zombies

Range: all zombies on the screen

Usage: single use, instant

Sleeps during the day

Ice-shroom frowns, not because he's unhappy or because he disapproves, but because of a childhood injury that left his facial nerves paralyzed.

Cost: 75

Recharge: very slow

Standard levels
Plant Ice-shroom when tough Zombies are trying to eat your other plants.

Against Dr. Zomboss, the Ice-shroom can be used to destroy fireballs and also to freeze him, so he can be damaged for more seconds at a time. The Jalapeno can be used in a similar way, destroying iceballs.

Note: Try to not spam them in the boss fight. When he puts his head down, use them in 5.5 second intervals to maximize the freezing time, until you feel that he is going to go up.

In Survival: Endless, it is an extremely useful plant, especially in cobless set-ups, where the few seconds gained with the Ice-shroom matters. It may be a good idea to plant an Ice-shroom before it is needed so it can be saved for later, but this may not work if there are hard-to-stop Zombies that could get to it and eat or crush it. They are normally placed in the pool or near the back of the lawn, where zombies pose less threat.

In the iOS versions of the game, freezing 20 full-sized zombies with a single Ice-shroom will earn you the 20 Below Zero achievement. The Ice-shroom can be planted anywhere and still freeze all on-screen zombies. It can also be used during Invisi-ghoul to show you where the zombies (on the land) are.

Whack a Zombie Mini-game
Use the Ice-shroom when you need a little extra time to whack a large wave of zombies. If you have enough sun, you can take that time to drop a Grave Buster at the same time. Use this only during the later part of this level, as there will be more zombies.

20 Below Zero
To get this achievement, you need to freeze 20 zombies with a single Ice-shroom. The two best places to do this are Last Stand and Survival: Endless, where the zombies come in big numbers. However, make sure to bring a Coffee Bean to wake the Ice-shroom up. Level 2-10 is also a good option.

Trivia

 * It is the only mushroom and one of two plants that can stop zombies and one of only four plants that can slow zombies. The other plants able to slow zombies are Snow Pea, Winter Melon, and Iceberg Lettuce. The other plant that can stop a zombie is Kernel-pult.
 * Its power is similar to Iceberg Lettuce's Plant Food ability with a slowing effect.
 * It is the only freezing plant in Plants vs. Zombies that does not reappear in Plants vs. Zombies 2.
 * It is the only movement-restricting plant that does not use a projectile to restrict movement.
 * Ice-shroom, Doom-shroom (when exploding), Fume-shroom, and Gloom-shroom are the biggest mushrooms.
 * Ice-Shroom and Doom-shroom are the only instant mushrooms.
 * Ice-shroom and Blover are the only plants that have a known childhood story.
 * Ice-shroom has icicles like the Snow Pea and Winter Melon.
 * Ice-shroom, Fume-shroom, Doom-shroom, and Gloom-shroom are the only mushrooms that frown.
 * It might have been injured, as its face is always in a frown, and his Almanac entry states that it was in an accident.
 * When an Ice-shroom explodes, snowflakes can be seen.
 * Ice-shroom is one of the twelve plants that appear in the seed selection screen after you get Grave Buster on the online version, the others being Cactus, Lily Pad, Potato Mine, Threepeater, Tangle Kelp, Jalapeno, Spikeweed, Torchwood, Tall-nut, Doom-shroom, and Blover.
 * There are three zombies that cannot be frozen or slowed down by Ice-shroom. They are Zomboni, Zombie Bobsled Team (when they are in the Bobsled), and Digger Zombie (when he is underground).
 * It is the only explosive plant that is not an instant kill. It does do damage to all zombies on screen, but that damage is the equivalent of a single pea.
 * Ice-shroom, Potato Mine, and E.M.Peach are the only explosives that do not burn zombies into ashes.
 * When used on a Pool or Fog level, the pool's animation stops until the zombies are unfrozen.
 * Ice-shroom, Grave Buster, and Umbrella Leaf are the only plants that can prevent Surprise Attacks from occurring.
 * Since the Almanac says that the damage is very light, it's actually the same as damage from one pea.