I did these zombie looks myself using liquid latex, a tube of either grey, red or flesh tone makeup.
I always wash my face first.
Then I use a sponge and apply some of the latex. Let it dry then powder it and dust off any sitting powder.
Then I apply a second coat of latex. Before I let this layer dry I put some torn tissue paper in the wet latex. I let this dry and then apply a third layer of latex. After it dries I powder it and dust off any powder left.
Then I make a tear in the tissue paper and latex and pull it up to look like a wound. In the picture with the bloody cheek I stuffed some baby wipes I soaked in fake blood into the wound. In the picture with the torn open cheek I just played with the material until I had a torn flesh look.
Then I painted the area around the wound using flesh tone and reds to give the look of injury. In the grey pics I covered my entire head with liquid latex. To save time I put my paint in the latex before applying it.
Then for the grey zombie I used dark eye shadow around the eyes.
On all the pics I splattered a little fake blood to make it look like I had taken a bite out of some fresh meat and been sprayed.