Properly known as Albert Lester he used to run the hospital in the Arklay Mountains. When his wife Dorothy died he was devastated. He found a plant which had become infected with the T-Virus and it devoured the corpse. As the plant grew it became hungrier and hungrier. He got people to follow him in his human form luring them to the hospital in which then he would kill them in his axe man form and then feed the body to Dorothy.
 Constant Pursuit
Throughout the events of Resident Evil: Outbreak File #2 in the level Flashback he will constantly pursue the player after he has lured the player into the hospital. The player has a decision to make constantly whether they will try and fight him off or they will run from him and hide. Through the level the player will discover it's better to hide around corners and walls and such as he only sees what is in front of him. Through hiding the player can stay safe and hidden and avoid his attacks from his axe. Though he is a constant pain as he follows the player throughout the whole level and won't stop. His attacks can be a pain to avoid sometimes if he has trapped you in a smaller corridor but in open parts he is very easy to avoid.
The Axe man dies when the player finally kills the plant known as Dorothy and has a time limit to escape the collapsing building. The player has to run out to escape but will meet the axe man somewhere along the way as he's coming the other way. As the player escapes and the ending sequence plays the player will see the axe man has finally gone back to the plant to tend to it as the building collapses upon him.
The axe man appears to have some sort of virus which allows him to have a great recovery ability and to take minimal damage. He will run off from the player after taking a certain amount of damage though can appear in the next run fully healed. So this speculates he must have had some form of the virus in him for this ability.