The Walker is a creature that lacks any special abilities. They will walk through the maze at a moderate speed and will stop to attack the player if they get in the way.
No special abilities.
Their weakpoint is the red "eye" on the front of their bodies.
Walkers take full damage from all towers. Slows combined with area of effect can deal with them effectively in bulk. Walkers will aggro on to the player and as such can be baited away from the maze, giving your towers more shots.
Walkers take full damage from all weapons and towers and their weakspot is very easy to hit.
Sniper rifles and shotguns can kill Walkers in one shot in the lower levels, if you hit the weakspot.