All my Dragonvale posts are being Indexed HERE for easy access.
Edit: I have added the possibility of trying for Ketu + the other event dragons to the bottom of the post.
The first limited dragon has been added to the Winter 2020 Event. The Ketu Dragon. It is a regular element dragon, with Cold, Air & Dark. I have put together the stats from a few different methods of breeding it.
3 Element Breed
Ketu has a 3% chance of being bred, when its 3 elements are in the breeding combination. That means you can use a multitude of different dragons to try for it. You want to use dragons with short breed times for breeding, because they will occur frequently in the fails due to their cloning bonus. The 2 dragons with the shortest breed times that cover those 3 elements are Snow + Frostbite.
There are only 11 combinations, so each regular dragon has a 10% chance of occurring. With the bonus cloning rules, Snow will occur 1 breed in 5, and the rarer Frostbite will occur nearly 1 breed in 10. But Ruin has the same elements as Frostbite, and has a breed time only 2 hours longer. So let’s check the % when we use 2 regular dragons in the breed combination.
Now with Ruin and Snow taking up 40% of the fails, the average fail time is down to 10.58 (12 minutes shorter).
Ruin + Snow is the recommended breeding combination to try for your first Ketu.
3 Element Breed + Social Clone
Once one of your friends is sharing a Ketu for you to breed with, your chances go way up. You have the chance of breeding it, plus the extra 4% of cloning it.
Ketu + Ruin will give you a 7% chance of breeding it, with the shortest fail times. You’ll have an even money chance of getting one, after non-stop trying for a little over 4 days.
Ketu + Longcicle
There are some possibilities of breeding a Ketu whilst you are trying for the other event dragons. Longcicle has the Cold and Air elements when you breed with it, so you only need to add the Dark element.
Breeding your Ruin dragon with a friends Longcicle will give you a 3% chance of getting a Ketu and a 5% chance of getting a Longcicle. With an average fail time of just under 12 hours, 9 attempts will give you an even money shot at getting one of them, on your 5th day. If you don’t speed up any fails, you can try about 15 times during the week that Ketu is available. This will give you a greater than 70% chance of breeding Ketu or Longcicle.
Ketu + Lyuba/Neyvee
Adding Dark to the Cold, Air, Earth and Water that Lyuba brings, makes a lot of possible dragons.
We end up with 109% of set breeding times. No regular dragons will be bred, and it reduces the outcome of Ketu from 3% to 2.75% and Lyuba drops from 1.5% to 1.38%. Average fail time is also nearly 15 hours. You will have 12 attempts in the week Ketu is available, assuming you breed non-stop and don’t speed up any breedings. You will only have a 40% chance of breeding Ketu or Lyuba in that time.
Neyvee has 5 elements when you breed with it, and you need to add Dark + Air. Just trying for Neyvee on it’s own lowers it’s chance of cloning to below the 1.5% it starts with. 7 elements adds far too many possible dragons with a set %, so I have not made the table.