top 3 possibilities

1) Chuck Norris
2) The Flying Spaghetti Monster
3) Space Republicans

my 3 possibilities :p

1. clones of themselves

2. Sharks *ones with freakin laser beams attached to their heads*

3. sea bass

i Agrea that its probably their nano tech, as their systems use it and in the tech tree they use it to enhance the live of the population by putting them in their blood, so maby nanite controlled advent people? that may explain why the lone suviving ship of the dark fleet was driven to insanity???

rofl

Okay since were joking about I think

zippy bungle and george

And all , planets lost the tune can be heard
Sings....
"Up above the streets and houses, rainbow flying high! Everyone can see it smiling RAAAINBOW .........etc"

Must be there uber broadcast centres putting out the death tune ^^

E.T dad.

Fools, it's so obvious.
They tried to make a Fallout sequel, turned it into a FPS, and the NMA mob found out.
The massive flaming on the internet boards created a raging supertroll, now devouring the galaxy.

mr. rogers...and his neighborhood...bam.

You can just tell that they were ANDROIDS, end of.

Look, their crazy creator sent out spybots into the Vasari, TEC and Advent empires and took samples of their cells and took photo shots of their orbital structures and samples of nano bla bla bla. For years he created the ultimate fleet which looked just like the people from these factions. And gradually he sends out them droids to exterminate the 3 factions. He obviously went for Vasari because they are an ugly and horrid species, then he's gonna go for TEC because that was he previous homeworld, they threw him out because they did'nt believe that war and conflict would overcome their world. And then Advent, becuase hmmm its the last of the 3 factions.

or following the storyline:

the crazy creator sent out spybots into the vasari empire, replicated their ugly mugs, copied their structures and technology and made the same ships. Everyone looks like a Vasari thing but this is where it all started 'FROM WITHIN THE EMPIRE'

cool, eh?

Its definateley the BORG!

that would bite those kill everything

A nanotech controled science vessal gets attacked and captured by the beast it creates a super intellegent race that decides that the varrsi must be assimalated and begin a crusade aganst them hunting them to the ends of the universe but now if u notice the other races have yet to encounter it so it must eather be single minded or maybe it knows if it comes out there will be trouble cause the advent seem like geniuses that would stop it

I don't really think the nanobot theory makes much sense, because the Vasari are being chased. Last time I checked nanobots weren't really built for long-distance travel.

The Vasari also don't know what has been chasing them, so they obviously can't "learn their lesson" because they don't know anything about whats chasing them.

One more point against the nanobot theory is that if a heavily damaged ship came back it would be rapidly falling apart- that's what nanobots do, deconstruct things.

I don't really think that an inorganic explanation will be the right one, mainly because they would never program something to slaughter them and pursue them thousands of light years through space. And if they had the level of technology to program sentient androids it would be specifically stated in the lore.

That leaves us with another race/a race they created is trying to kill them. I think either of these would work as an explanation. But I'm leaning towards a new race, not a Vasari slave race. Mostly because they say that they harshly assimilated any races advanced enough to pursue them as fast as they could flee. Its strange because the manual seems to both hint at and hint against the slave race uprising scenario.

The most probable pursuers are bio experiments, mainly because of the lab shown in the opening sequence, but, if they were an incredibly strong intelligent adaptable race, then they could probably accomplish as much as my final possible scenario.

Despite this, I think that there is another, more advanced race pursuing the Vasari and forging an incredibly vast empire with the technology to destroy the entire dark fleet before they can even give the order to retreat.

Btw the beast r an organic race of homeworld that take over technologey and assimalate it and some nano tech have collective intelgence so when there r few they dont have much intelgence but many nanobots would have a lot more intelegence

Actually It's a race thats basicly way more powerful than the vasari. There will be an expansion coming out for Sins and this new race will be playable along with a few other new races. Also a campaign. I'm not sure what kinda of Alien Race is chasing the vasari but there pretty powerful. I think this information was leaked on some sites.

It's the big floating beer can and ping pong ball from star trek 4. the vasari don't have any humpback whales, so they can't stop it.

you guys have to remember that it is something the Vasari created. if u guys were paying attention.

I agree. Stop blaming the Vasari for beer and ping pong!

The most evil entity the universe has ever seen - RIAA

Nibblonian - http://en.wikipedia.org/wiki/Nibbler_(Futurama)

or

Brainspawn - http://en.wikipedia.org/wiki/List_of_recurring_alien_characters_from_Futurama#Brainspawn

Jack Thompson. He's gotta be ticked.

a whole swam of nerds wanting to make the whole univers into a super computer to find the question to the great answer 42.

Top 10 theories of things or people chasing the Vasari

10. William Shattner's old toupee
9. The Orange dude who "Hankered for a hunk of Cheese" from the old Schoolhouse Rock cartoons. (It's a Wagon wheel!)
8. An Inconvienient Truth.
7. A Carlos Mencia sketch gone wrong.
6. The result of Bill Clinton not inhaling.
5. Angry race of aliens striking back at high gas prices.
4. Unknown race trying to expand their cell phone coverage but inadvertently destroying everything in their path (Can you hear me now?).
3. Contestants on the intergalactic reality TV show "Who Wants to Be a Harbiger of Doom?".
2. Paris Hilton's delision of being talented and important taking physical form.

And the #1 Theory of things or people chasing the Vasari...

You guessed it: Frank Stallone.

Wait!

If you people are saying that it's something the vasari have created, it must of been an inside job an rebellion of some sort, I mean come on. It can't be some bad experiment that they did, that went wrong. Mutated and revolted against them (Commies) Remember that Vasari are the tortureous sort of species that enslave beings to get the best outcome out of it all.

But it's fun to predict what will happen. I've got another thesis. Maaaaaaaybe...

It's there past ancestors that have mighty power that was forgotten over years. No one gave a crap about them because they were less technologically developed, but secretly they had an object which was powerful enough to transform minds against them just like in 'Transformers'

Who knows?

The Vasari created Halo 3, and distributed it throughout their planets. Everyone played it at the same time, and the shockwave that was created from every single one of their race screaming NOOB at eachother destroyed everything and is now travelling through space in super-sonic speeds, leaving nothing alive.

They would have created it, so it supports that theory.

Then it would not be another race but an unstoppable wall of brain-melting sound.

Imagine a large cloud devouring and assimilating everything in its path that your weapons have no effect on.  It could be quite unsettling.  The nano pest may have originated as a phase capable resource mover, moving materials across intersteller distances.   Although it would have to incorporate fleets if it was to be included as a playable race.