Lord of Dragons

Bestow {7}{w}{u}{r} (if you cast this creature for its bestow cost, it is an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature)
Enchanted creature has +7/+7 and "{t}: put 3 +1/+1 counters on this creature." If enchanted creature is a dragon, it gains an additional +3/+3.
{t}: put 3 +1/+1 counters on this creature.