Thing's you should take into account 

1: I'd like you to stick with one picture for both your dragon and the breed
2: for features that's things like horns and spikes on his body so yours would be the two black horns on his head
3: Size can't be "gigantic" give an actual measurement or reference to your average 6ft male 
4: your stats have a max of 20 each but take note that because he is young, you can't have him know how to do everything when the rp starts
5: He's more of a stoker breed since his abilities and habitat revolve around fire, the mystery breeds usually shoot something other than fire like toothless and that one dragon who uses lightning...my horrible memory, anyways since he is your dragon and is now known, it would make sense that maybe he was first classified as a mystery breed but then put into the stoker class, like the zippleback when they were first in the fear class but once they were discovered they were moved to the another class (contemplating removing the mystery class due to the fact that I know a lot of people will want mystery class dragons)
6: abilities would be like how zipplebacks can connect necks or how toothless can make his teeth retract, it's not a necessity to have though but maybe you can say his horns glow when he charges up a blast

EDIT

Added a new thing to the CS called how you met your dragon, you can make up a short story about how you met your dragon or you can plan to meet them during the rp, just let us know in the CS