this is what I think happened to the creepers to make them explosive.



Once, in a kindom named Minecraftia, a peaceful mob was born in the heart of a dungeon. It's name was creeper, it had freckles and was green. In minecraftia, all the mobs were friends and there were many different mobs, one of them was herobrine... herobrine didn't like being friends with all the mobs. He despised steve and the villagers so he plotted to destroy them.

he sneaked up on creeper and knocked him out, he then dragged creeper to a table and stuffed a block of tnt and a fuse inside creeper. Herobrine cut the arms off of creeper. when creeper woke up herobrine told him that steve had stuffed explosives into him and cut his arms off, this made creeper mad, very mad. creeper attacked the villagers and turned into a hostile mob, that is when a war broke out. creeper got zombie, enderman, enderdragon, wolf, skeleton, spider, jockey, ghast, wither and zombie pigman to fight the peaceful mobs. now minecraftia is at war for eternity and stev and his friends must save minecraftia from peril.