enderdragon is going to X:0 Z:0

Ender Dragon is always go to X:0 Z:0 in overworld

i was bored... so i just spawned Ender Dragon in Overworld

and, Ender Dragon was go to X:0 Z:0 .-. i add the vidio. please see it and fix it
Describe what happened here

Steps to Reproduce:
1. spawned Ender Dragon
2. going to X:0 Z:0
3. always in there .-.