Like Bruce, I am skeptical.
Rats need to move, and move through small spaces, to live. I don't see how this could do that.
Rats are selfish buggers that fight amongst their own kind. If there was a rat king starting, I would expect that they would fight it out, chew off each others' tails, kill each other, etc.
I can almost imagine someone catching a goodly number of rats, and having them tied together with twine around their tails, then as the rats die, the result is what we see here. Maybe.
I'd rather imagine that than imagine a rat king, still alive, running down an alleyway towards me.
