Oh, it is a long, convoluted tale, but here we go (though I doubt anyone will read this post; much less care)
Long ago, I was known (not on here) as MissNemesisFace. In one of the early volumes of the Hellsing Manga (vol. 1, I think), after remembering how Integra and Alucard met, Integra asks him what he thinks of her. He calls her "Margaret Thatcher" and Seras calls her "Miss Nemesis Face". My friends started calling me that, and it stuck.
Over time, I corrupted it to Nemmeh (my current username).
Finally, it was shortened even further to Nimh (and also as an homage to "The Secret of Nimh", the animated movie, and to The National Institute of Mental Health. Despite the fact that I'm super polite and kind on here; minding my Ps and Qs and all that noise, I am nutty in real life). Gradually, that became "NimhShambler" as both a reference to the aforementioned references for Nimh, but also to a Magic: The Gathering card (though it is spelled "Nim Shambler"). As soon as the name-change thread opens up again (and I can be arsed to get over there), I'll probably change my name to NimhShambler to match everything else.