|New Enemy Units||None|
There are 3 cerebrates here, each with different powerful abilities. The red cerebrate (northwest) makes the sunken colonies around your base invulnerable. While there's a ring of unbuildable terrain around your base to stop you from doing anything stupid, you won't get any ground attacks out until that's dealt with. The brown cerebrate (northeast) will send out the Torrasque periodically. The Torrasque is "a whole cargo-ship of whoop-ass," in your Marines' words, and will respawn every so often to rip apart your defenses. Make sure you have plenty of bunkers and siege tanks around your base, and expect to lose some a few times before you get the hang of it. The orange cerebrate is near the Overmind, and will mainly keep to itself. However, once you destroy the other two, it will start to send Infested Terrans. They can take out a bunker easily if they get close, but your siege tanks will get them first. Fortunately, the rest of their offense is fairly light. The occasional six-pack of hydralisks, a wave of zerglings, and sometimes a group of mutalisks to mix things up. Very rarely, a couple guardians will attack, so keep a few valkyries or wraiths handy to counter them.
The Red Cerebrate
Once your base is secured with bunkers and siege tanks (Cover all the entrances, or you'll discover any weaknesses as soon as the Torrasque shows up.), you can climb the tech tree towards Battlecruisers and Yamatos. Build at least 4 BCs and a group of Valkyries or Wraiths to cover them (Valkyries are better against massed air units, but wraiths will deal with pesky hydralisks on the ground.). Now fly towards the red cerebrate. If there's a spore colony in the way, two Yamatos will level it. Order your BCs to all use their Yamatos on the cerebrate and then swarm it for the kill. Meanwhile, have your other air group draw fire and take out any mutalisks or hydralisks that threaten your BCs. You'll take some damage, but as soon as the cerebrate dies, all its units go dormant, and the sunken colonies are finally vulnerable.
Now may be a good time to expand to the east, where your starting bunkers were. The extra resources will be very useful, and if you can control the choke point to the east, you'll find it easier to catch Torrasques before they do too much damage.
The Brown Cerebrate
The brown cerebrate is well-defended from the air, with spore colonies lining the ridges, hydralisks scattered around the base, and devourers, whose acid spores make every attack all the more painful. Your BCs may not be the best option, though they'll do quite well at defeating the Torrasque, and you can use them to remove some of the Sunken colonies in your path. Build up Siege Tanks and Marine/Medic groups with Science Vessel support, and slowly grind your way up through the base. Once you're in range of the cerebrate, focus fire on it and it should fall quickly. Brown's troops will fall dormant and you won't have to worry about Torrasques anymore.
Alternatively, if you have a large group of Battlecruisers (6-8), you can fly to the north of the narrow pass, where you'll find only a few Spore Colonies and scourge. Once you clear them out, you can wait to recharge your Yamatos and repeat the same trick you pulled with the Red Cerebrate. However, you'll want the extra BCs because Brown has better air defenses, and you'll run out of Yamatos otherwise.
However, the cheapest and quickest solution is to land a shuttle-load of infantry on the ridge east of your eastern base and have them work their way east and north, killing Spore Colonies and Hydralisks as they go but followed by a few Wraiths to kill any interfering air units. Reinforce with at least one Siege Tank and SCV. When you reach the ridge's northern tip, build a Missile Turret and have your Siege Tank bombard the Brown cerebrate. This plan allows you to bypass the Red cerebrate instead of destroying it.
The Orange Cerebrate.
If you said "Battlecruisers" as the answer to how you'll attack this cerebrate, give yourself a round of applause. Since enemy attacks are light without the Torrasque, take your time and build a full group of 12. Fly to the northeast corner of the map, and slowly move west towards the cerebrate. There's a line of spore colonies in the way, but you should only need 6 yamatos to deal with them. Then, Yamato the cerebrate and it'll die quickly.
Another solution is to plant Siege Tanks on the eastern edge of the continent, using the island immediately south as a staging area. Gaining the low ground is not usually a good tactical move, but in this case it will protect your artillery until you can safely move a couple of Tanks up to the main level and bombard the cerebrate.
With all three cerebrates dead, no Zerg will oppose you. Walk your medics up to the beacons, and enjoy the cinematic!