Nightstalker Scarecrows/Dopplegangers Regiment

Doppelgangers are faceless, silent, yet spine-chillingly creepy. No matter how desperately the enemy fights, they match them blow for blow, slowly changing to mimic them until the enemy is staring at their own grinning faces.

The zombie-like Scarecrows are always right behind you, shuffling relentlessly and endlessly no matter how far you run.