Draikus like Oculus, are created via a mutation. This one, however, is both more subdued and less likely to occur.
Every one in one thousand Enderians have a chance of producing the Draikus mutation, factors showing they have the mutation being the appearance of horns.
It's incredibly common for an Oculus mutation holder to also have the Draikus mutation, however with Oculus being a dominant mutation they tend to turn into Enderian Oculus, simply displaying horns of a Draikus as well.
Should a Draikus grow old enough, they may advance to the next stage in their life known as an Elder, these are quite rare however but heavily implied to be a stage just before evolving into an Ender Dragon.
It is unknown how long Draikus live, the oldest one rumoured to be reaching a hundred thousand years before finally passing to old age, they age at a similar rate to other Enderians, however stop this process to retain their prime in their late 60s.
However, due to this ageing process, they begin their time as a draconian quite weak and grow into their strength in their later years.
This process can, however, be forced through magical means.