What kind of sewing foot is this?
 

Brought some sewing items home from my prior home, while putting items away here I found a box of assorted presser feet. Even though I have been sewing like forever I wasn't familiar with what they were all for. During research online I found out what most were and how to use them. But I could not find this one. Any one know what it is used for? thanks and God bless!

Looks like some kind of a walking foot, maybe a pleater.

I'm thinking maybe a pleater. Don't see any rubber "feet" under it to help push fabric through like my walking foot has. Try it out and see what happens.

I haven't seen anything like it. I don't know what it might be.

Could it be a cording foot. Fabric under the foot cord or ribbon over top and under next bit. Mum had one but no longer with us and can't remember what she used it for forty years ago.

In the top picture, it looks like an attachment Mom had that was for attaching bias tape to an edge. The side view does not look (to me) like what I remember Mom's looking like. Cording foot may be right.

I believe it is a gathering foot. The fabric you are gathering would go over the top of the front part of the foot and the part you are sewing it to would go underneath the foot. Or it could be the opposite way, but it looks like one part will feed with the needle going up and down, I just don't know for sure which one.