The frenzy dog is a magical transformation of almost any other animal, created by the special create frenzy dog spell, used by the druids of Chondalwood to protect their environment. The spell that creates these creatures is barely known outside this forest, and the druids use it sparingly, creating a pack of only around a dozen frenzy dogs at one time, wary of their ability to ruin forest environments if left unchecked. A frenzy dog gains a certain amount of magical intelligence, but only enough for hunting.
The frenzy dog is around 4 feet (1.2m) tall at the shoulder and has black coat with tan and white swirls. It has a face similar to a pit bull. It has a protrusion of 7" (18cm) bony spikes from its neck that has the appearance of a spiked collar.
A frenzy dog eats three times the amount that a normal dog of the same size would eat. They will eat any type of animal flesh.
In combat, the frenzy dog attacks without fear and attempts to rip its victims apart (although not necessarily to eat). It has the ability to go into a rage which will grant immunity against animal empathy or handle animals, it can trip humanoids and other bipeds, and it is hard to grapple due to the spikes around its neck.