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Werewolves frenzy when overwhelmed by their Rage. Mechanically this occurs when they achieve too many successes on a Rage roll. While high Rage character can perform spectacular feats, they are also more prone to frenzy.

In frenzy, the Garou ignores wound penalties, automatically assumes Crinos form, and fights with his full strength. In a Berserk frenzy, he will fight until everyone is dead or he breaks free of frenzy. He may well attack packmates because he is unable to recognize them as friends. In a Fox frenzy, he flees in terror, tearing through anything that gets in the way of fleeing.

If they achieve a truly spectacular number of successes, they may enter Thrall of the Wyrm. These horrible frenzies seem to indicate that the Wyrm has tained the Garou natural Rage. Thrall comes in three varities, based on breed.

Lupus Garou in Thrall will attack their own fallen packmates and deliberately try to kill them. This is atrributed to the influence of Beast-of-War.

Homid Garou in Thrall will attempt to devour the flesh of fallen comrades and foes, engaging in cannibalism. This is atrributed to the influence of Eater-of-Souls.

Metis Garou in Thrall will rape fallen packmembers and foes and engage in necrophilia. This is atrributed to the influence of the Defiler.

Garou generally lose renown for frenzying, but how much varies by how severe the frenzy was. Entering Thrall will always result in a loss of renown. Some Garou will even commit suicide after entering Thrall as they now believe themselves irredeemably tainted by the Wyrm.