The Echo Zek is a "mini boss" of sorts and one of the more dangerous variations of Zek. Only Two are encountered throughout the game.
A sickly, almost emaciated looking Zek, with grey skin, grimy pants, complete with heavy duty boots, and a face stuck in a permanent glare. And most interesting, a sharpened, bloody, plank of wood, complete with nails, attached to its right arm with what appears to be rope and tape.
It is a good idea to use the Volk S4 Shotgun when fighting it. It will constantly be phasing and you never know where it is until it reveals itself to attack. Using deadlock is a good idea but it will still be very fast. The best strategy is throwing a Cryo Tank at it and killing it with one shot.