Ok, lets go:
- Drop Rate of Falcon Items on Mini-bosses: 1 : 2,500 (there is a post from CM confirming this, but I cant find it now)
- Drop Rate on Cobra Mini-bosses: Unknown
- Drop Rate on Oberon: 1: 200
- Drop Rate on Scarlett: Unknown
On Falcon Castle you CAN trap every falcon in rooms (the only exception is the roof) and run freely from boss to boss, I'll show a map on where I trap them:
Rooms marked as YELLOW, is where you have to trap the Falcons
SURFACE:
+1
+2
+3
+4
With this you can run from boss to boss and you'll only met falcons at the roof.
.
My route is:
- Island
- Table
- Monk
- Roof
I'd say Cobra bosses seems to have a much higher drop rate, and they also feature the Ugly Monster
which can drop basically every cobra item, and it seems to be higher chance than even the bosses themselfs.
So, if I had to choose, I'd camp Cobra Bosses.