These are the number of times I bred two of the same normal monsters and got a mythic monster:
|Monster||Number of Tries|
I have a theory about Shiny Monsters. After breeding mythic fires for a very long time I started to see a pattern: I was much more likely to get a mythic fire if I already had a mythic egg in the nursery (or at least it seemed that way). I was getting so many mythic fires. Then I tried to breed a mythic plant. It took me 15 tries. And then I bred a Flower monster and a Bug monster and got a purple and green egg. I checked to see what it was and found out I'd bred a mythic flower without even trying. At this point I still had the mythic plant in my nursery. I hatched the flower, bred two plants, and immediately got a second mythic plant. I'm not saying you're gauranteed to get a mythic egg if you already have a mythic egg in your nursery. I'm just saying that I'm starting to suspect it increases the chances. I'm going to start paying attention to this to see if it is true.