A Trojan Mongorian Horse is a deceptive weapon inspired by the infamous Trojan Horse that the Greek's used to trick Troy during the Trojan War. The difference being that no one is inside of a Trojan Mongorian Horse, because it is filled with Sweet and Sour Pork, a substance known to be hot and sticky and the main weakness of Tuong Lu Kim (aside from being Asian, having English as a second language, and being subject to the worst possible speech impediment that could result from those two qualities), owner and manager of the City Wok in South Park, Colorado.
"Oh I get it, a Trojan Mongorian Horse. Mongorians are hiding inside, tinking that I bring it in da' shitty wall, d'en Mongorians pop out and destroy shitty wall from da' inside out without gettin' da' sweet and souwa pork on day head. Okay, I'll pray arong" - Tuong Lu Kim
Blapping is a way of describing a sudden surge of proficiency in a first-person shooter. It doesn't mean you perform poorly normally, it's just a way of expressing that you are particularly satisfied with your performance. It's most often used shortly into a round after enough time to evaluate whether it's going to be a "good" or "bad" game in terms of your performance.
The term derives satirically from rap and hip-hop music where rappers use it as an onomatopoeic representation of gun (usually handgun) blasts. Alternatively, it may derive from being a jackass and yelling it out the window of a moving vehicle trying to scare pedestrians.
The need for the word can be partially attributed to the fact that "pew pew" isn't appropriate for conventional, non-energy weapons, and thus an equally expressive sound was needed for firearms.
Wow I'm blappin' on fools this round!
I just blapped this dude so hard!
I'm about to get my blap on!