Halloween Event coupons

[InspirAsian]

At DNSEA
There is this event going on:

You need 3 coupons to exchange for an 3,5,permanent pumpkin head
There are 4 different heads.
I was wondering if there are particular dungeons where alot of these ducks will spawn..
I only need 3 more coupons for having the last on permanent..

[xBoredom]

in DNNA they spawn a lot in the 9-16 dounguns and i get like 2or3 a run. Not sure where they are in DN SEA.

[InspirAsian]

Ahh, I only get 1 sometimes... And when I'm in party, I roll the dice low. -_-