Hemathion not spawning (rare mob)

[Boogietroll]

What is the bug?
The bug is that Hemathion, a big rare dragon in Blade's edge mountains is not spawning. I've been looking for him for several days, more than once a day and I cannot find him.
Is it a spell or database issue? (database relates to any NPC, quest or item)
Database(?) Since it's a mob that is not spawning.
How can you reproduce it?
-
Please describe, in detail what is suppose to occur when this bug happens:
The mob is supposed to spawn-
Please describe, in detail what happens when it bugs up, and how it's malfunctioning:
-