Unlike the raven, the crow's claw attack deals physical damage instead of causing blindness. This gives the crow two physical attacks to the raven's one, and although each 1d4 individual attack deals less damage than the raven's 1d6 bite attack, in combination they can do one more point of damage than the raven.
Also, unlike the solitary raven, crows are social birds that appear in the dungeon in large groups. A player caught in an open space by a flock of crows may soon see why this variant makes the collective term "murder" especially apt for crows.
The binding spirit Malphas ("Prince of Crows") has a special affinity for crows.
A player who has bound Malphas gains a +2 bonus to AC and to-hit for every crow on an adjacent tile. The player also has the active power to summon a tame crow.
When Malphas is bound into the Pen of the Void, there is a chance that an enemy killed with the Pen will be replaced by a tame crow. The probability is 5% before the quest nemesis has been killed and the Pen restored, and 10% after the quest.