Ice-shroom

Ice-shroom freezes all the zombies on the screen for a few seconds. It is single use, to activate it just drop it in any empty spot on the screen. After a second, the Ice-shroom will freeze every zombie on the screen and do a slight amount of damage to each one. Zombies will have ice at their feet like ice sculptures. Zombies will unfreeze after a couple of seconds, but then will be slowed for a few more seconds

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 the 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. In Survival: Endless 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 it. In iPhone/iPod Touch/iPad version of the game, immobilize 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

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.

Trivia

 * The Ice-shroom is one of the only three plants that have ice crystals on their body. The other two are Snow Pea and the Winter Melon.
 * The Ice-shroom is the only plant that fully immobilizes zombies by freezing, the only other plant who immobilizes zombies is the Kernel-pult but he uses butter.
 * Although the Almanac says Ice-shroom damage is very light, its damage is actually equal to a pea. Therefore, 10 Ice-shrooms would kill a normal Zombie, 28 for a Conehead Zombie, etc.Ice-shroom_Seed.png
 * If an Ice-shroom is sleeping, its eyes won't be seen. The same happens to the Scaredy-shroom.
 * The Ice-shroom is the only plant that has a purely a light blue hue. Both the Snow Pea and Winter Melon have green and light blue colours.
 * The Ice-shroom is one of the six plants that frown, the others being the Gloom-shroom, the Fume-shroom, the Tall-nut, the Torchwood, and the Doom-shroom.
 * The Ice-shroom is counted as an explosive plant as you can see a blue flash with snowflakes when it freezes all the zombies.Snowflakes.jpg
 * The Ice-shroom is the only plant that can attack every zombie in the screen simultaneously.
 * The Ice-shroom & Blover have the largest area of effect among all Area of Effect Plants.
 * Coincidentally, Ice-shroom and Blover are the only plant with a childhood history in the Suburban Almanac, Ice-Shroom when he had a childhood injury, and Blover when he was five years old.
 * In the Plants vs. Zombies website, the Ice-shroom looks mad.
 * Ice-shroom is one of the twelve plants that appear in the seed selection screen after you get the Grave Buster on the online version, the others are: Doom-shroom, Lily Pad, Potato Mine, Threepeater, Tangle Kelp, Jalapeno, Spikeweed, Torchwood, Tall-nut, Cactus and Blover.