I have not a damn CLUE where I got this, other than one of my friends (IRL) liked to say it a lot (and since I've not heard it in a while, I may have messed it up a little):

A low level newbie mage yell this.
Vare yells "not in the face, not in the face!"

funny but you might of had to be there

Shaolong yells 'For the Spam !!!'
Arulf yells 'Spam for the Spam!! hurray !!

a low level mage saying "i think i can, i think i can..... #### i cant" and runs away

its not much of battle cry but verry funny (at least for me)

Frantak says : can I take this beastie ?
Shaolong says : Nope,at least for ten levels more.

Frantak's slice barely scratches Neptune.
Neptune's blast ****SMITES**** Frantak !!
Frantak is DEAD !!!!

Shaolong sniffs and says 'they never learn...'

Kill the smurfs!

a dwarf saying aaaye laddy ill show em what my dwarven axe feels like,

For the honor of the great Intarne,
Slay the Isp Beast !!!

if the gods wont help me, with the hell with them.

i think i got that right from connan

"SPOOON!" -The Tick

A gnome child smiles at you.
A gnome child mauls you!
You wish that your wounds would stop BLEEDING so much!

Smiling is just about the scariest battle cry I've ever seen.

"All your base are belong to us! Ha-Ha-Ha"
("Somebody set us up the bomb!")

[edited - another quote]

You smile at a black monk
black monk smiles at you

You thwap black monk for being a moron
black monk thwaps you for being a moron

You throw an alligator at a black monk
Black monk's hit ***DEVASTES*** you !!!
You wish your wounds stop BLEEDING that much !!!
You flee head over heels !!!

-he DEFINITELY doesnt likes alligators :)-

"Suicide is the answer"

RELEASE THE CRACKEN!

"Kill all women and rape all men!!!"
(It's from a Viking sketch in an old Dave Allen show.
Viking number two says, "Don't you mean the other way around?"
Whereupon number one retorts: "Mate, you do it your way, and I'll do it my way.")