User blog comment:Catman3/Breeding Poo/@comment-11259553-20130819122800

It's a very common complaint. Poo seems to be something of a special case. It functions more like a level exclusive in that it is more likely when using a wildcard than everything else about the wildcard suggests it should be. I'm not sure why it works that way internally.

If the odds formula is still working, I would say Poo is not a difficulty 1 as it's listed in the calculator, because that results in obviously wrong odds. (I am don't know if the odds would be any better with it at a different difficulty though.) I'm not sure how accurate the odds formula still is. It often gives very high/low probabilities that don't seem to fit with breeding results, but it's hard to get large sample sizes for most pairings.

The element combinations side of things are close, if not perfect in all cases.

Legend + [dragon with 1 or 2 of Poo's elements] seems to be the best way to get Poo. According to Richmond Nguyen Legend + Terra returns Poo at the highest rates. I've seen many people get Poo with that, Legend + Mud, or Legend + Waterfall after trying for weeks/months with the 'conventional' breeding of hybrids. So I'd try one of those three formulas if I were going after Poo.