The Gates of Xerpius
The Blood Drinker (Blade) +2 Lvl 9
Weapon: Axe or heavy blade
Enhancement Bonus: attack rolls and damage rolls
Critical: +1d6 damage per plus
If you make an attack using this weapon and miss all targets, the blood drinker deals 5 damage to you, and the next attack you make before the end of your next turn deals 2d6 extra damage to the first target it hits.
You know when to feed your weapon, because it growls when it’s hungry.