User blog:Brigadier Barty/The Greatest Threat to Redwall Abbey

Redwall Abbey has seen many, many foes in its time, from Cluny and his horde to a band of Water rats working under a scheming Marlfox under cover of night.

But this certainly begs the question-

Of all the enemies seen, who has by far posed the single greatest threat to the Abbey of Redwall?

You may judge this by numbers, intelligence, quality, sheer luck, or other factors you find important.

Submit your answers below and I'll create a list.