An alghoul's basically a badarse ghoul.
— Yarpen Zigrin, dwarven warrior
Alghouls differ from normal ghouls in size, strength, coloring and, most importantly, intelligence. Whereas ghouls and graveirs are primitive creatures unfit to plan even the simplest ambush, alghouls and their kindred (such as cemetaurs) are capable of forethought, and are thus much more dangerous.
Ghouls seem to possess wits enough to at least know a brighter mind when they see it, and so let alghouls and cemetaurs lead their packs. A pack so led will terrorize all in its path, attacking not only lone travelers but also caravans and even farmsteads. When encountering such a pack the alghoul should be eliminated as a first priority, leaving the other beasts for once their leader is gone. One be particularly careful when fighting alghouls around dusk and at night, when they fight with doubled strength.
During combat alghouls and cemetaurs try risky maneuvers aimed at knocking their opponents to the ground so the others can finish the job by tearing them to shreds. Like a normal ghoul, an injured alghoul can fall into a frenzy and attack with blind fury. An experienced witcher knows to get out of its way on such occasions and strike from behind, while for an inexperienced witcher, such a turn of events often marks the end of his Path.