The Legged Turret will not move at all until you get in it's range, if you do, it will charge at you at increased speed. If you're fast enough, you'll distract it. Sometimes it will hit a wall and sometimes stopping and looking around. Either way, it takes 10 seconds before they can become passive again.
Also, the Legged Turret can rarely be seen in many different variations, such as a sideways legged turret. Also comes in a defective version, wandering around and looking at any nearby players.
The turret part is the exact same as the other normal turrets are, while the legs are longer than the standard turret legs, making them taller in comparison. They also have a wheel at their back.
This turret can still be destroyed using lasers. However, it'll try to avoid them.
The turret itself is the speed of a Combine Soldier from Half-Life 2.