Drakoni may be bred together in any combination you can think of. Offspring will have at least one of the parents' elements, sometimes even three or four in parents with a lot of elements!
In order to breed Drakoni, your Breeding Chamber must be empty. Once the breeding is complete, you can put the egg in the Hatchery to be hatched.
Drakoni have breeding cooldowns, which are listed in the breeding roll.