The priest casting this spell calls upon the "spirits" of wolves (or another animal, if appropriate). The notion of wolf spirits is akin to the Wild Hunt of Celtic mythology: a pack of enormous magical wolves led by a human master who range Celtic lands seeking to destroy evil. The wolf spirits spell summons 2d4+2 such entities to serve the priest as master.
Wolf spirits' statistics are as follows: AC -4; MV 36 Fl 36 (B); HD 5+5; #AT 1; Dmg 3d6; AL N; SZ M; ML 20; THAC0 14. They are immune to all forms of mind control, illusions, gases, paralyzation, and spells which affect only corporeal creatures. They cannot be harmed by weapons of less than +2 enchantment.
Wolf spirits can be instructed to perform a service in the manner of the Animal Summoning I spells. In this variation in the Animal and Summoning spheres, the spell does not expire until the spirits have performed their commanded service, to a maximum duration of 14 days. In the Guardian variation of this spell, the spirits can only be commanded to keep watch over an area or creature. The spell lasts 100 days for this type of service.