This TreeFrog Whistle works very well. It sounds great.  I made it from wonderful and popular [https://www.printables.com/model/3116-treefrog](https://www.printables.com/model/3116-treefrog) and [https://www.printables.com/model/495173-flat-pocket-whistle](https://www.printables.com/model/495173-flat-pocket-whistle) and then merged them into one model.

I found it prints best with supports, but you must check the box “support on build plate only” to prevent supports from forming on the inside.