Chocolate

Chocolate is an item in Plants vs. Zombies. It is used to boost the productivity of the Zen Garden. It can be obtained in all game modes with the exception of Zen Garden itself.

Description
Chocolate can be fed to Zen Garden plants and Stinky the Snail. When fed to Stinky, he will move much faster and will not fall asleep for one hour. When utilized on plants, chocolate will cause them to drop money at approximately four times the normal rate. Once ten pieces of chocolate have been amassed, no more chocolate will appear. But if nine pieces of chocolate are in the player's inventory and two or more pieces are spawned, then eleven or more pieces of chocolate can become available at once. The player can also hack using cheat engine to earn as many as you want to.

Chocolates will not appear until the player purchases Stinky the Snail from Crazy Dave's Twiddydinkies.

How to Get them
Also, see Money Guide since you get money the same ways you get chocolate.
 * Randomly from killing zombies.
 * Occasionally eating a brain in I, Zombie.
 * A streak of three in I, Zombie Endless.
 * A streak of ten in Vasebreaker Endless.
 * Sometimes after a Grave Buster eats a grave during a night level, or during Versus Mode.

Trivia

 * When chocolate is used on Stinky the Snail, a siren known as "mindcontrol.ogg" can be heard.
 * This is the same sound as when a zombie eats a Hypno-shroom.
 * Despite the fact that Chocolate is used in Zen Garden, it is not purchasable from Crazy Dave's Twiddydinkies.
 * This makes it one of the three items for the Zen Garden that can't be bought, the others being the Watering Can and Zen Garden Plants.