Black Ghost Knife myth busters needed

I've probably seen hundreds of black ghost knifes in my life. Who hasn't?
After recently seeing some nice ones at my LFS I thought hmmmm, might be cool to keep one in a tank by himself, so I got on the net to do some basic research.

The info I found varied so much that I'm pretty confused, mostly on how big a BGK can get. I've never seen one over say 10-12" but according to many sites I've visited, some say they can get 20"-26" in length. That's believable to me since so many other knifes like carapo, aba-abas, etc. get huge, but alas, I've never seen a black ghost knife that big, not even in a photo. What do they look like as large adults and how big do they REALLY get? Are they evil killers as adults? Do they fade into a putrid grey and lose the white markings with age?
Pics pleeeez!

Wow, he's a beauty. Elephant looks nice too. Well there's one question answered. Your knife seems to be retaining his color nicely for being large and relatively old.
What I'm really hoping is that someone will post a pic of a 20" specimen or give the link to a site that has a photo of one that big. I can't find a photo of a jumbo BGK on the web anywhere.
Thanx Miles!

!!!! That's huge!!!! Well, looks like I'm back to square-one on not knowing how big a BGK can really get but I appreciate the feedback. Still haven't found any pics on the web with some guy holding up a giant Black Ghost Knife the length of his own arm.