I am a tiny, severely underweight female, therefore the thing I should be most capable of taking out in hand-to-hand combat is yaks. Clearly. Have you seen those things? They're ferocious. I can clearly murder the crap out of them. With my hands. I slay them left and right.
Mostly the username stemmed from my friends and I talking about whether we'd survive bear attacks and such. My friend Ken told me I could totally take on a yak. So I made it my Xbox Live name and have used it for literally everything else since. The End.