Nine Tails is a Demon Unique helm with no boss attached: it drops anywhere in Nightmare, most often from N8 up (rarer below that home difficulty, never above it), and nowhere else. Every copy is item level 100, and there 0.3% of what falls comes up Unique. It is built on Sovereign Foxhood Helm — step 6 of the Foxhood Helm line, item level 80 and up.

It always rolls the same numbers: +6% Critical Chance, +28 Armor, +327 Maximum Health, +8% Critical Chance, +30 Armor, +12% Critical Chance, +29% Attack Speed and +45% Fire Damage.

One Unique drop in 40 is a Mythical copy: the same item carrying 15–25% Mythical Energy that boosts every stat on it and can never be changed; the 15% floor is 10 times as common as the perfect 25%.

On top of that it carries Nine Tails — Main repeats +1; Main damage -10%.

“Count them twice; the number changes.”