The Spawn system in A Dawn of Heroes will consider your character ECL from any Race or Subrace when deciding which creature to spawn. NOTE: This means that a level 1 Vampire (ECL +3), will spawn creatures as for a level 4 normal human. XP will be higher, but also the challenge. Be careful.
Unique Creatures Chances:
EACH creature that you will spawn has a % chance to be "Unique".
Unique creature will be stronger and harder to kill compared to their normal version.
Killing these creatures will be harder, but will award more XP and a chance for better loot(compared to loot provided by same not-unique creature)
Unique creatures can be much bigger than their default models!
Also, an Unique creature will have the double chances to drop Vengeful gear.