The Origin:

In Strong Bad's ninety-fourth email, Strong Bad discusses video games he could possibly be in, and one of them is called STRONGBADZONE (by Videlectrix of course). It consists of a "3D vector game" where the player is a "spiky-haired 3D cybershield guy". Strong Bad's head would move back and forth at the end of a tunnel, and girls would try to make out with the screen, causing him to command in a jarring, mechanical, and echoing voice, "BACK OFF, BABY!" Naturally, you can't control Strong Bad, so he would move regardless of where you wanted him to go. Out of Strong Bad's mouth would shoot "perplexing geometrical 3D attacks", and you would have to deflect the shapes back at the taunting, but incredibly handsome, three-dimensional Strong Bad face. If you hit him enough, he dies, but if you get hit, you "face certain 3D doom," and Strong Bad declares his victory: "YOUR HEAD A SPLODE." The blatant mistakes in that phrase would be due to translation problems.

After the email has concluded, you are allowed to select any of the four games included in Strong Bad's rambling, and play them. To move your character, use the left and right arrow keys. To raise your shield in different positions, press A, S, and D. STRONGBADZONE is also available to play in the Games section of the Homestar Runner website. In April of 2006, Strong Bad answered his 150th email by visiting the Strong Bad-doppelgangers of the Homestarrunner universe, including Vector Strong Bad. He greets people with a friendly "HELLOTE", and a hipper "WHAT IT IS MY DOGE?" He also elaborates on his purpose in life (to "SPLO STUFF UP"). Later, when all the Strong Bads sing Save the Last Email For Strong Bad, he gets the line "I HOPE THEY DON'T A SPLODE", referring to some children. That sums up Vector Strong Bad's appearances thus far.

But do not worry, citizens of Strongbadia! This website doesn't need to be the only place to hear such an epic remark. In the Homestar Runner online store, a "Your Head A Splode" T-shirt is available. If that's not enough, why, you could yell it yourself. The phrase "YOUR HEAD A SPLODE" can be used in so many situations.

Examples:

Insult to injury.
Person A: I have damaged my cranium!
Person B: YOUR HEAD A SPLODE.

Poor memory.
Person A: What was that gentleman's name again? I cannot for the life of me recall it.
Person B: YOUR HEAD A SPLODE.

Information overload.
Person A: I was up all night studying. I feel as if my head will explode.
Person B: YOUR HEAD A SPLODE.

Strongbadzonial situations.
Person A: Please sir, cease this barrage of perplexing geometrical shapes!
Person B: YOUR HEAD A SPLODE.

Self-Deprecating.
Person A: I apologize for not helping you earlier. MY HEAD A SPLODE.

E2 Catbox.
IWhoSawTheFace is the undifferentiated blastomere cells, ready to morph into anything.
<AudieMcCall> Just don't let some chick rip your nucleous out, I Who.
<IWhoSawTheFace> Oh, it's happened countless times, Audie, and will continue to do so.
<IWhoSawTheFace> But I'm very zen about the whole ordeal. Like water, one must flow around teh obstacles and thus render them of no consequence.
<artman2003> What if a beaver dams your water up, IWho?
<IWhoSawTheFace> My head a splode.

Now, all together now, in your best 3D-vector-game robot voice...

"YOUR HEAD A SPLODE!"