The monsters are called "Walkers," they have dark skin and may resemble human. However, they have several mutations that assist in the spread of the virus. They have black eyes with red pupils. They have the full range of emotions and are indeed sentient. They all have a high healing factor and are arrogant. Assuming humans are weak and they are above them. They crave flesh and blood. They have formed their own society with those with yellow eyes being extremely powerful. They can speak.