Minecraft – How to kill a summoned ender dragon

With the new summon command 1.7.4, you can summon a enderdragon on a minecart. Then it will still look to you but it can't fly away. You can also give it custom names. :-) Here is the command.... you can make these commands with the new summon program

Use /kill @e[type=EnderDragon,r=100] while you are in the same dimension as the Ender Dragon you want to kill. This command doesn't require any command blocks, so you can just type it in the chat.