Expired means you can no longer breed it... although this dragon is unique anyways, because as long as you have all the of the necessary decorations, this dragon can be evolved from a Gift dragon.
The only ways to get an expired dragon are:
1) through mystery eggs (including gifts from visitors)
2) if it's an evolved dragon you must have all the required decorations
3) breeding: one parent must be the target dragon (unless it is an evolved dragon, then both parents must be the target dragon)