Half-Umbral Dragons are only rarely the result of Umbral dragons mating with other creatures—most are the result of strange magical experiments. In most cases, a successful creation breeds true with others of its kind, as with the dreaded dracolisk.
"Half-Umbral Dragon" is an inherited or acquired template that can be added to any living, corporeal creature (referred to hereafter as the base creature). A half-umbral dragon retains all the base creature's statistics and special abilities except as noted here.
CR: Same as the base creature + 2 (minimum 3).
Armor Class: Natural armor bonus improves by +4.
Speed: A half-umbral dragon has wings. Unless the base creature has a better fly speed, the half-umbral dragon can fly at twice the creature's base land speed (average maneuverability).
Melee: A half-umbral dragon has two claw attacks and a bite attack. If the base creature can use manufactured weapons, the half-umbral dragon can as well. A new claw or bite attack deals damage as appropriate for the half-dragon's size.
Special Abilities: A half-umbral dragon retains all the special attacks of the base creature and gains a 30-foot cone of negative energy that deals 6d8 points of damage, usable once per day. A successful Reflex save (DC 10 + 1/2 half-umbral dragon’s racial HD + half-umbral dragon’s Con modifier) reduces damage by half.