From Destinypedia, the Destiny wiki
While a Scorn Walker appears largely the same as a contemporary Fallen Walker, looks can be deceiving. The Scorn replaced most of the Walkers weaponry and upgraded its defenses. In place of the repeating Arc cannon at the front of the Walker, a deadly flame thrower ensures enemies keep themselves at a distance. For those at a distance, make sure to take cover, for instead of a large cannon, the Walker fires volleys of missiles that search for any present target. When damaged, a large dome shield surrounds the Walker preventing enemies at a distance from inflicting more damage. The one feature that remains unchanged is its shock wave defense should a player get too close.
Fortunately, despite these deadly upgrades, the majority of the Walker's weaknesses remain. Its leg joints and primary engine core remain as priority targets that players should aim for.
If you damage the walker too slow, (due to a glitch) it will start to bug out and have infinite health.
List of appearances