Well, I see a lot of excellent suggestions here. So if I may be so shamelessly self-promoting, I'm going to do a bit of lobbying now for the names I've proposed.
Seeing that several other posters (dullone, BillyJoeBob, RifRaf, and beyondmyken) have pretty much echoed my suggestions of "Rat('s) Tooth" and "Rat('s) Fang", I suppose that's an indication that a name like this would have a certain appeal to knifeknuts. The judges will, no doubt, take note of this fact.
However, my personal favorite is "Whispering Rat." As I see it, this fits nicely with the existing product naming scheme (or, at least, one that could be inferred) behind the "Howling Rat", which is also a 4-1/2" blade.
And besides ... if a 3/16" thick, tough-as-nails, SR-101 rat "howls", doesn't it make sense that a stealthy, sleek, super-slicing rat made from 1/8" D2 is going to "whisper"? Tell me that people won't feel they have to own both -- sort of the yin-yang of Swamp Rat bladeware, Howling Rat and Whispering Rat.
As for "Son-of-a-Rat", well dang it, I wouldn't have suggested it if I didn't like it! But other than that, I can't think of any additional, compelling reasons for the folks at SRKW to choose this name over others, 'cept for it just sounds tough, and kind of cool.
Now, to make this even more interesting, I'm going to make an offer of my own: if SRKW chooses to name this knife the "Rat's Tooth", "Rat's Fang", or "Son-of-a-Rat", I'd like for the give-away knife from this contest to be awarded to someone serving overseas in our armed forces (I'll be glad to let Eric, Jennifer, or members of BFC decide how the lucky recipient will be selected.)
And if SRKW should happen to decide on the name "Whispering Rat" ... well, under those circumstances, I would just have to have the give-away knife for myself, and so will pay SRKW for a second one to be shipped to some deserving man or woman in uniform.