Learn the silhouette. Read the threat.

Two threats shown in official imagery[1]
Marcus confronting a towering Locust in official E-Day imagery

Locust Drone

Infantry with armed and aggressive variants.

An armed Boomer surrounded by fire and rubble

Boomer

A heavy threat with an execution vulnerability at low health.

From the first swarm to the commander

Where to start in the field guide[2][3][4]
ThreatWhat to understand
WretchThe early unarmored swarm and later armored variant.
SeederA large supporting threat with its own entry.
ReaverAn aerial creature encountered around the invasion.
VraahkThe Scorched Legion's commander, introduced by The Coalition.

The Locust Field Guide also covers armored variants, heavy enemies and Horde Invasion Events. It separates a battlefield enemy from a large event creature.[2][5]

Two encounters. Different ways to win.

Campaign boss guides — Adam Stewart / Gamer Social Club gameplay captures[6][7]
Brumak towering over fleeing civilians

Brumak · Act 1

Open the campaign encounter guide.

Corpser confronting a Gear in an industrial interior

Corpser · Act 3

Open the campaign encounter guide.

Watch the mouth. Watch the sky.

Two new threats[8][9]
Bilefrog with its green mouth open

Bilefrog

Open the combat guide.

Spore Matron beside a building

Spore Matron

Open the combat guide.

Sources for this overview
  1. Gears of War: E-Day official game page
  2. E-Day Multiplayer Deep Dive
  3. Gameplay reveal deep dive — Official Xbox Podcast
  4. E-Day Campaign: Brotherhood and Hope in a Hopeless World — developer transcript
  5. Emergence Begins — Tomorrow: launch weapon tuning and enemy fixes
  6. Firsthand Brumak encounter: Act 1, Chapter 4 playthrough, screenshots and video
  7. Firsthand Corpser encounter: Act 3, Chapter 2 pillar phases, screenshots and video
  8. Firsthand Bilefrog mouth-explosive achievement method
  9. Spore Matron reveal: original Gamescom interview with Nicole Fawcette and Aryan Hanbeck