Centipede. The ones around here (korea) don't grow much bigger than 4-5 inches as far as I know, but that one in the video appears to be a larger variety and since it's kept in captivity and well fed, it'll probably keep growing until it's cardio system can't keep up and it dies.
The one I found looked almost exactly like a smaller version of the one in the video, except for the color. Mine was mostly black instead of reddish brown.
They're poisonous and moderately aggressive (ie. will bite humans even if not unduly provoked), but they don't seem to be too common either. That's probably because they're predators and need their own territory so you just won't find swarms of them.
