Chicken with mud daubber like covering on leg/foot

[farmgirl63]

I have a koshen hen, sweetest thing ever, and she has mud dauber like covering that has grown over her foot...
I tried to break this off and it made her bleed so I gave it up, didn't want to hurt her..But WHAT is this? I have never
ever seen anything like this before. Obviously its making her cripple...she doesn't move around much but waits for me to
feed/water her very close by in her little corner of the chicken house.

 

[Pyxis]

Do you have pictures? It would help us to figure out what it is if we could see it.

 

[Eggcessive]

Look up scaly leg mites either here on BYC or Google it for pictures. Bad ones look like a build up of scale.