Quest for the Lost Duck

[StateOfTheArt]

Ok, so I'm trying to find and beat every NPC duck so I can get an arena badge. I've looked everywhere, but I'm still struggling to find the missing duck (or ducks). If any of you know of any well-hidden ducks, hidden caves and their locations, or something along those lines, giving me some information about them would be very appreciated. Thanks!

[TheRedOwl2007]

Go along the lake that starts behind the egg island tournament although i am missing one too and have no idea where

[AmazingJx2]

How many NPCs are there?

[TheRedOwl2007]

no idea