Half Life 2: Episode One

[Necromancer]

Enemies

Drones - Flying enemies, that come in various forms. Most of the time, the Gravity Gun works fine against them.

Scanners - In the beginning of the game they might be harmless, after a short time they'll become annoying machines that'll blind you and find you, so the Combines can easily spot you.

Man Hacks - These are updated version of the Scanners. Not only do they fly, but they also have a small blade spinning around, which isn't nice at all. Just keep slashing it with your Crowbar to take it down. The Gravity Gun
also works fine against them.

Drones - Flying things, that'll drop Hoppers down.

Flashers - They are annoying little things. They'll move towards you, and try to blind you. If you just look away from them, you're fine though.

Civil Protection - The enemy you'll battle most. They are some sort of super human (Über-menschen (the army Hitler wanted to create back in WW2), perhaps? Who knows.), and are available in various tastes and smells.

Combines - These are the guards of City 17, and are the main enemy throughout the game. They are dressed in black, and appear to be human, but who knows. Sometimes they are only equipped with a stun-stick, others are equipped with heavy weapons. There are various of these Combines, ranging from the city version, to the prison version. Not enough difference to discuss, though.

Combine Snipers - You'll notice them by the blue laser. Take them out by tossing a grenade or mine in their hideout.

Super Combines - White Combines, that are stronger than any other Combine you encounter in the game. They are the only Combine that'll use the secondary attack of the Pulse Rifle.

Headcrabs - The annoying enemies from the original Half-Life. Most will die from one hit with a Crowbar, though.

Black Headcrab - These Headcrabs are poisoned, and when they hit you, you'll get poisoned too. When you got hit, just stand still until the suit healed you.

Civil Protection Equipment - The vehicles and other unfriendly things the Combines will use against you.

Missile Tanks - These tanks will shoot missiles at you. Just keep moving and you'll be fine. Fire at the missiles, so they'll miss you, when you really need to.

Gunships - These are even more annoying than the Helicopters. They'll fly around and shoot at you. Only the RPG can take them down. They require 6 rockets before they go down.

Strider - Big creatures, that have long legs. You probably know them from various Half-Life 2 screenshots or movies. They require 6 rockets, before they'll go down. This means you'll need to find one of those boxes with unlimited rockets in them.

Sentry Guns - Turrets you can just pick up, place somewhere, and they'll shoot the enemy. You can easily take them down with Gravity Gun, or by throwing something towards them.

Zombies - Huuuuuuuuuuuuuh... that's the sound they make. Some are slow, others are fast. Shoot them in the head, if you can.

Zombies - These poor guys got attacked by a Headcrab, and turned into Zombies. They'll throw things at you, so be sure to watch out. When the Zombie died, the Headcrab might still live, so watch out.

Leapers - These aren't your average Zombies, they are way faster, and are able to climb. Take them out with your Shotgun.

Zombine - A Combine that became a zombie. When it feels like it, it'll grab a grenade, hold it in its hand and then explode. Quite handy when it's away from you, since it'll take down his friends too.

Piggy Tail Zombies - Even stronger Zombies. These guys have a load of Black Headcrabs on them, and won't hesitate to throw them at you. Take it down quickly.

Mines - What needs to be said? Step on them, and get yourself killed.

Roller Mines - Strange enemies, and easy too. Pick them up with your Gravity Gun, and shoot them as far away as possible. Alyx can modify them, so they'll attack the enemies.

Laser Mines - See the red beams? Don't touch them, because a mine will explode if you do.

Hopper - An advanced type of mine. They'll only attack enemies. However, if you pick them up with your Gravity Gun, and place them back on the ground, they'll work for you.

Antlions - Like the name makes you suspect, this is a mix between a lion, and an ant. They'll fly, and attack you. They'll keep coming, so move away from them.

Antlion Warrior - This is the advanced version of the Antlion. They'll summon Antlions and rush at you, trying to hit you.

Barnacles - You should know these enemies from the first Half-Life. They just hang at the ceiling, with their tongue out of their mouth. As soon as they feel something touched their tongue, they'll slowly move the object towards their mouth and try to eat it.

Stalkers - They used to be people, but now they are just slaves of the
Combines. Watch out for their lasers.

[Necromancer]

Alies

Barney Calhoun - The security guard from the original Half-Life. Although you saw many of his clones, in this game, there is only one Barney, and he seems to remember you ("Hey Gordon, it's me, Barney, from Black Mesa").

Dr. Isaac Kleiner - Another old friend from the original Half-Life. This time, there aren't clones, but just one Dr. Kleiner. He has a pet, Lamarr, and he seems to care more for her, than for his own life.

Alyx Vance - The daughter of Eli Vance (more about him in a few seconds). She helps you in the game at various points, and see seems to be a better shooter than most other allies. Also, many gamers have a crush on her.

Dr. Eli Vance - The father of Alyx Vance, as stated above. He has a strange leg, but he's friendly, so don't worry.

Dog - The pet of Alyx Vance. It's not a real dog, but a robot. It's extremely strong, and help you in various ways.

Dr. Judith Mossman - Don't want to spoil the original Half-Life 2 for you.

Rebels - They contain the most stupid A.I. of the game, but it's still better than nothing, right? You can take up to 4 with you, and they'll aid you by shooting enemies, and giving you health (the medics will do this, obviously).

Vortigaunts - They were enemies in the original Half-Life, but that's because they were slaves of Nihilanth. Since you saved them, by defeating Nihilanth, they are friendly now.