So my chicken has had a foot like this for a couple of month. I finally caught her today and it's warm to the touch. I had one that got it near her eyeball and she died a few months later
It looks like bumblefoot, both the bulb and the scab between the toes. What does the bottom look like? You may need to start soaking the feet in warm Epsom salts water to soften the bumblefoot. Sometimes you can open a scab and get out the plug of infection out. The bulb-looking one may be more liquid pus. Surgery is generally done on bumblefoot, but you can try the soaking first and proceed to surgery later. Here is a good link with details of bumblefoot treatment: https://the-chicken-chick.com/bumblefoot-causes-treatment-warning/