Anybody know what this may be?

[Bmsky]

Not sure what this may be, any info or help is greatly appreciated.

 

[LaFleche]

To me this looks as if the full crop is somehow pressurized to the side and back. The crop region is not particularly well feathered.

But you could take the chick up to have it sit on your hands without any pressure to the crop to see, if it disappears.

 

[SheaLoner]

Is it soft and squishy?

 

[Ursuline Chick]

looks like a growth or cyst to me.

 

[Peas4Ducks]

Does it feel like it’s full of air? Possibly a ruptured air sac