How to Breed Poo Dragon in Dragon City
Poo Dragon is now an exclusive dragon after the July 2013 update. If you want to see the full breeding chart, click here.
To breed it use:
Any Legendary(Nirobi, Droconos, Wind, Legendary, Crystal or Mirror) + Armadillo or Dark
If you want to be sure, make sure your parent dragons are level 10 or higher.