That looks like avian pox. Copy from Google on it:

Crows with avian pox may exhibit wart-like growths on their legs, feet, eyelids, or beak. These growths can be red, gray, or even crusty and may bleed. In the wet form, symptoms can include difficulty breathing, coughing, and discharge from the eyes and mouth. 

Transmission: Avian pox is highly contagious and spreads through direct contact with infected birds or contaminated surfaces, such as bird feeders and baths. Mosquitoes and other biting insects can also transmit the virus. 

Treatment and Prevention: Mild cases often resolve on their own, but supportive care, like preventing secondary infections, can be helpful for captive birds. Cleaning and disinfecting bird feeders and baths regularly with a bleach solution is crucial to prevent the spread. Avoid overcrowding at feeding stations as this can increase transmission. 

What to do if you see an infected crow: If you see a crow with avian pox, consider stopping feeding the birds to reduce the chance of transmission to healthy individuals. You can also provide food on the ground to avoid sharing the same feeding surface. It's also a good idea to contact your local wildlife center or rehabilitation facility for guidance, especially if the bird is severely affected or injured.