Creeper

Creepers are tall, explosive mobs in Minecraft that will explode if you are near them.

They are the first mob of Minecraft and was a failed pig model when Notch tried to add pigs. Creepers chase any player within a 16 block (±5%) radius and ±4 blocks vertically. The detection range of creepers is reduced to 8 blocks when the player is wearing a creeper mob head.‌

When within three blocks of a player, a creeper stops moving, hisses, flashes and expands, then explodes after 1.5 seconds. A creeper's detonation can be halted if the player leaves the blast radius of 7 blocks, including by knocking back the creeper or killing it.