Creepers are harder enemies than Zombies, at the same level as the Skeletons. Creepers are unique because they actually have a number above them, that starts at 8 for the first seven worlds and at 4 for the last two. Each turn, it goes down by one. If it hits zero, the Creeper explodes in the face of the last attacker, instantly defeating them or causing at least 92% damage, but heavily injuring or defeating themselves in the process.
Upon defeat, they collapse to the floor. After another turn, they also explode, but deal only 25% of the damage.
Flyin' Kick: The Creeper jumps forward into the air and smashes itself onto it's target, dealing 20-45 damage. Taken directly from older versions of Minecraft.
Super Implosive: The Creeper explodes. It's a one-hit KO for characters with less then good DEF (e.g. Bob, Alex), and deals critical damage to character with above average DEF, like Steve and Clavicle.
Silent Boom: One turn after being defeated and falling to the ground unconscious, the Creeper explodes, dealing 25% damage.
Dream Creepers are Creepers that lie on the floor, peacefully sleeping... well, at least until you attack it. Like all other dream enemies, D. Creepers do not have to be defeated to win a fight. Also like all other enemies, they (mostly) only truly attack if you wake them up, at which point they throw a pillow at you, then go slumbering again.