SRD:Bodyfeeder

Bodyfeeder: All feeder weapons have a special ability that functions only upon scoring a successful critical hit. A bodyfeeder weapon grants its wielder temporary hit points equal to the total damage dealt by a successful critical hit. These temporary hit points last for 10 minutes. Thus, if the wielder of a bodyfeeder weapon successfully scores a critical hit while the wielder still enjoys temporary hit points from a previous critical hit, the wielder gains only the better of the two values: either his current number of temporary hit points, or the new influx of temporary hit points, whichever is higher.

Strong psychometabolism; ML 12th; Craft Psionic Arms and Armor, claws of the vampire; Price +3 bonus.