Answer:
7 Dragons.
Explanation:
16 dragons 6+ dragons gone
12 griffins 3+ griffins gone
Let's say one more than 3 griffins are gone: 4 griffins are gone.
Then:
Griffins now = 8
Dragons now = <8
One less than 8 dragons is 7 dragons.
In the end, 4 griffins and 9 dragons had left.