The ender dragon is a hostile mob that spawns once in the end, is 16 blocks long, and can kill you instantly. Upon entering the end dimension, you will spot the dragon, a great black monster of a creature, swooping round. The key step to defeating it is to destroy the end crystals which sit upon the Obsidian pillars. The best way to do this is to stay down on the ground and shoot arrows/ throw snowballs, because if you got up close, the ender dragon could knock you off and kill you. The reward for defeating the dragon is its egg, which appears on the bedrock plinth after you have won the game.