Cerberus

Firstly, it is important to note that Cerberus is a specific type of creature, and not a generic Zombie Dog - which was the result of a random t-Virus infection on a regular Dog via an outbreak. The Cerberus was scientifically engineered as an early B.O.W (Bio-Organic Weapon) by Umbrella scientists. They believed that a canine would be a good choice to begin with as a species as they can be trained and have been successful policing and military dogs for years.

Cerberuses are Doberman pinschers infected with the β strain of the t-Virus, an early attempt by Umbrella to create a deployable B.O.W. for sale to the military.

Initially considered a success by Umbrella, trouble began after the initial t-Virus outbreak in 1998, where they escaped. Without a supply of food or training to keep them from becoming too aggressive, they turned feral and began attacking and eating anything they could find.

The dogs themselves have typical t-Virus characteristics such as decomposing skin, enhanced durability, heightened aggression and very little in the way of reasoning. However, with the right personnel, Cerberuses can be trained to follow orders to a degree. Unfortunately, it was far too late after the outbreak, the insatiable hunger and degeneration that the t-Virus brought was too much and their violent instincts had taken over.