Natural Selection/Alien lifeforms

Skulk - 2 Resources

 * Recommended Upgrades
 * Regeneration, Silence, Cloaking (Assassin)
 * Carapace, Celerity, Scent of Fear (Grunt)

The lifeform everyone spawns as. I hope your good at this one, or otherwise your Alien career will be best spent as a Gorge. They have the ability to climb along walls and ceilings, allowing them to get into perfect ambush points. They move very fast, and are practically breaking the sound barrier with Celerity. They don't have much health, so avoid going up against a Marine at long range - because he'll kill you before you get anywhere near him.

Bite - 75 Damage
The main attack of Skulk. It takes 2 to kill a Marine, and each armor upgrade they have allows them to take 1 more bite. Obviously, its a melee only weapon, so you'll need to get close. Biting also blocks your view temporarily, because apparently the Skulk's eyes are in the middle of its mouth... despite they're actually on his head. Anyway, get good using this weapon, because it's lethal in the right hands.

Parasite - 10 Damage
A handy little "attack". Basically, its a projectile you shoot out from your mouth, where upon contact with a Marine, they become parasited. Parasited Marines show up on your team's hive sight, so they know exactly where the Marine is at all times. Parasited Marines rarely live long, as your team can know exactly when to ambush him. If travelling with a group, they then give away the location of the entire group. The only way to remove the parasite is to die. You should parasite Marines whenever possible, especially those you know you won't be able to kill.

Of course, Parasites do an insanely small amount of damage... so if your able to parasite somebody to death, it should prove quite embarrassing. ^_^

Leap - 4 Damage
Another one of the Skulks attacks that really isn't an attack at all. This attack makes the Skulk leap through the air very quickly, greatly reducing travel time. Leap can hurt someone however. That 4 damage can strike multiple times, depending on how long your pressing against someone while leaping. Still, its usually a better idea to use Bite.

Xenocide - 200 Damage
This is what makes Skulk useful in the end game. Xenocide takes away a large portion of your energy, but basically turns you into a time bomb. Upon activating, about 3 seconds later you'll explode violently, obviously killing yourself in the process. Of course, hopefully there are enemies in the area when you do this.

A very potent combination is to use Xenocide, and then Leap IMMEDIATLY after. This will let you get into position very quickly, and allow you to pretty much bypass any defenses.

Gorge - 10 Resources

 * Recommended Upgrades
 * Redemption, Celerity, Scent of Fear (Builder only)
 * Regeneration, Adrenaline, Cloaking (Battle Gorge)

The backbone of the Alien team. These are the only lifeforms that can build, so they are essential if you want to win. Since everyone gets an equal amount of resource flow now, anyone can go Gorge and help the team. This is a great way for newbies to get used to the game, since you can help the aliens out, even if you suck at fighting. Read the Alien Structures section for more information.

Spit - 25 Damage
The main attack of the Gorge, which you should probably never use. It moves pretty slowly, making it hard to hit any enemies. Its the only long range attack the Gorge has however. You should avoid all combat as a Gorge unless you have some help, but in case you do run into a Marine, the following attack is probably the one you should use.

Heal Spray - 16 Damage
This should probably be your weapon of choice as the Gorge. It allows you to heal all players and structures, which is a nice touch. It has an area of effect, meaning you can heal multiple things at once. This is a pretty good attack against a Marine. Since it is area of effect, you can dance and jump around like an idiot without really aiming. This is going to make you pretty hard to hit, so hopefully you'll be able to kill him before he kills you.

Bile Bomb - 200 Damage
A very under-used attack. If you played 1.04, you probably knew how potent this attack was as a Fade. Be warned though - in 2.0, it does not damage people, only structures. Theres nothing funnier than seeing a Gorge trying to Bile Bomb a Marine to death. It is still an extremely effective weapon, however. Since it has an arc like a heavy ball, you can Bile Bomb turret farms and other structures from a safe vantage point. It also has a pretty large area of effect, allowing you to take out many things at once, or take out a turret from behind cover. A single crafty Gorge can take down any Marine structure with this attack, provided nobody comes to intervene - so have an escape route handy.

Web
Not really an attack, but a potent defense nonetheless. A Marine caught in a web wont be able to shoot, and have his movement slowed to a crawl. This effect lasts for quite a few seconds. Obviously, this will cause any assault to pretty much stop in its tracks, and the victims will be easy prey. Each string of webbing will disappear after it has entangled someone, so they will occasionally need to be replaced. Also, there is a limit to how many webs each time can have, so don't go crazy. Welders and Grenade Launchers can destroy webs.

To use webs, simply fire at the points you want the web string to connect to. So if you want a web to stretch from the floor to the ceiling, simply fire at the floor, and then at the ceiling. Note that there is a limit to how long the string can be.

Webs and Offense Chambers can be lethal weapons. Simply create a web trap for Marines to stumble upon, and then put an offense chamber nearby.

Webs are also lethal to Jetpacks, since they'll simply fall if they hit one - and thus easy prey for Skulks, Fades, and other lifeforms.

Lerk - 30 Resources

 * Recommended Upgrades: Regeneration, Celerity, Scent of Fear

Meant as a long distance support class, this guy can also function alone if your good. Spores are lethal to the Marines, since they can make a large group of them easy prey. Spikes are the only long distance attack aliens have early on, and can take down turrets from relative safety. Umbra and Primal Scream allow you to be useful in the end game helping out the bigger guys. You probably won't get as many kills with the Lerk as other classes (if your doing your job that is), but you'll definently be helping out the team.

Spike - 16 Damage
Insta-hit projectiles that are pretty potent little weapons. You can shoot them pretty quickly, and they take little energy. Marines tend to have more armor than you do though, so don't try to go toe-to-toe with one unless your hidden, or he's weakened.

Spores - 14 Damage per second
A great attack you'll be using a lot as a Lerk. This creates a cloud of gas at wherever you shoot, making life quite uncomfortable for any Marines in the vicinity. It doesn't damage them all that much, but it will probably take off about 1/4 of their life - leaving them easy to prey to the rest of your team, unless the commander starts to waste resources on Medpacks. So either way, you win.

A very potent, albeit a bit annoying attack is to hide in a vent near the Marine base and shoot spores everywhere, in particular the armory. If they want to get ammo, they'll get hurt - if they wait for it to wear off before getting ammo, that will be a lot of wasted time - and if they run off without getting ammo at all, they'll run out pretty quickly. Bast and Eclipse come to mind for this strategy.

Spores also do not stack - so be sure to spread them out! If you want to further damage Marines in a spore cloud, switch to spikes.

Umbra
This shoots out a cloud just like Spores, but this is one you'll want to shoot at your teammates. This cloud blocks 2/3rds of any bullets that pass into it. A Lerk spraying Umbra is pretty much required if you want to take down any turret farms. The cloud only lasts for 3 seconds, so replace it often. If a Hive or other structure is being shot, casting Umbra on it will make the attackers' jobs much harder. Umbra does not effect non-bullet weapons.

Primal Scream
A handy little attack that increases the movement speed, energy regeneration, and attack speed of any alien in the area. It also only lasts a few seconds, so be sure to scream again every once in a while. Any aliens that are effected will scream in reply, which just sounds cool if theres a lot of friendlies around.

Fade - 50 Resources

 * Recommended Upgrades: Carapace, Adrenaline, Scent of Fear

My personal favorite class, provided I have Adrenaline. The best way to use these guys are as Guerilla troops - blink in, do some damage, blink out, and heal. This guy is pretty much the only alien that can solo and do it well. Turret farms without phase gates easilly fall to the prey of the Fade, since you can keep widdling away at them until they die.

Slash - 80 Damage
Basically, a slightly more powerful version of the Skulk's bite. Unlike the Skulk however, you can almost always get close to use it - use Blink to almost instantly get in the enemy's face, and then just claw him to death. The main attack of the Fade, get used to it.

Blink
Oh man, I love this skill. This lets you move through the air at near light speed - just point and shoot. This lets you get into vents usually off- limits to higher classes, and lets you get pretty much anywhere very quickly. It uses quite a bit of energy, so try to have Adrenaline. Also, avoid holding the button down unless you REALLY need to get out of somewhere fast. Tap it for better results.

Metabolize
A skill that lets you heal yourself a small amount. And well, thats pretty much it! It will repair armor as well, so it lets you get back to 100% fighting condition anywhere on the map.

Acid Rocket - 50 Damage
The only powerful ranged attack the aliens have. This attack is often essential to finish the game, to "snipe" turrets the Marines may have set up in their base. It has a good amount of splash damage, and moves a little slow. It acts pretty much like a rocket launcher from any FPS, so try to jump and aim for the floor around your enemy.

Onos - 100 Resources

 * Recommended Upgrades
 * Redemption, Celerity, Scent of Fear (Heavy Armor Counter)
 * Regeneration, Adrenaline, Scent of Fear (Standard)
 * Carapace, Adrenaline, Scent of Fear (Kamikaze Onos O_o)
 * Regeneration, Silence, Cloaking (Scare the **** out of people!)

The heavy hitter of the alien team. Essentially walking tanks, they are the only effective counter to Heavy Armor. They are not the be all, end all unit though - they still need help from other lifeforms, especially Lerks, if they want to be effective. So just because you have 100 res doesn't mean you should use it all!

Gore - 90 Damage (double versus structures)
Funny how most of the slot 1 attacks for aliens are melee type attacks. This is pretty much your standard melee attack, except its quite powerful, especially against structures.

Devour
This attack is just so much fun. Walk up to a Marine, and CHOMP - devour him whole. A Marine will lose 3 HP per second that is given to you. It also keeps the Marine out of commission for a pretty long time. This is the best and pretty much only effective counter to Heavy Armor that the aliens have. If you are killed during the time you are devouring a Marine, he will pop back out. Also, if you Redeem back to the hive, you will expel your tasty snack.

Stomp
Tired of all those pesky Marines running around you, making them pretty hard to Gore or Devour? Give em a good ol' stomping. This attack sends out a shockwave that freezes any Marines it hits for 3 seconds. They cannot fire during that time either. This of course makes them easy prey to Devour or Gore, so use it liberally. Stomp and Devour is an extremely effective way to kill Heavy Armor.

Charge - Incredible Damage
Charrrrrrge! Using this attack slowly drains your energy until its gone, and really boosts your running speed. Anything you run into during this time will be hurt, a lot. It works a lot like Leap, the more time you have pressed against something, the more it will be hurt. You can easilly mow through an entire squad before they knew what hit them.

If your having trouble keeping "pressed" up against a building or player, try crouching. This cuts your movement speed in half, but doesn't reduce the damage.

A very evil way to use Charge is in conjunction with a Sensory chamber. Attacking will usually uncloak you - but Charge works a bit differently. You only "attack" upon activating Charge. So, if you wait around a second, and then recloak, you can charge all you want completely cloaked! Adrenaline is pretty much essential if you do this, since you won't have as much energy as you usually would.