Cactus

Cactus (plural: Cacti) is a block that inflicts damage to the player and mobs alike. Cacti can be naturally found in desert biomes. Cacti is the only solid block that makes mobs take damage. They can only be placed on sand.

Smelting

 * Cacti + Any Fuel = Green Dye

Trivia

 * Mobs in contact with cacti will make no attempt to move away.
 * Cacti cannot be grown using Bonemeal.
 * Cactus grows rapidly near waterbeds.
 * Cactus may also grow in mesa biomes in addition to desert biomes.