Woge

Woge (VOH-gə; derived from the German verb wogen "to surge"), named from the psychological impulse that drives it, refers to the act of changing between human and Wesen form; it is used as a gerund. In the Grimm series, English-speaking Wesen disregard the grammatical rules surrounding verbs, using anglicized forms "woge" and "woges".

As Woge is impulse-driven, a dead Wesen will woge back (or "retract") into human form. Likewise, a Wesen tends to enter Woge once they perceive something as a threat come close to their vicinity. As such, to voluntarily enter one without necessary cause could take a while, as seen in, where it took Monroe a few seconds to shift into his Blutbad form.

Monroe describes it as painful to some degree, but one eventually gets used to the sensation. Woge affects the Wesen's body, and also their intonation; as in the way they speak. It usually doesn't affect any item they may have on their person, such as clothing.

A Wesen in full woge will revert back into human form when it dies. However, if some parts of their body were to be removed before they revert back, then those parts will remain as it is, as seen in, where the hair that Juliette obtained remained as Wildermann hair even after Larry Mackenzie died.

At lesser levels of Woge, often triggered by emotion, a Wesen may reveal its true form only to Grimms and other Wesen within the vicinity. Normal people would see no difference. But if they so will it, Wesen can invoke their Woge to a level where their morphing could be seen by normal people.

Monroe once referred to the event as "the first time you 'fang out.'" It is hinted that it doesn't occur immediately after birth, but might at an early age. In, William Granger says that Drang-Zorns do not experience their first woge until around age 13. Until a Wesen woges for the first time, they may not be aware of what they are until such time. This is similar to how Grimms do not manifest their abilities until they are much older.

Many Wesen develop an ability to woge on demand by rolling their heads or other specific movements. Even when done by reaction, it is common for them to move their heads in some way, others may find it difficult to do on demand.

Outside elements may also cause some Wesen to woge. For example, the full moon can give Blutbaden an increased desire to woge. Even Wieder Blutbaden like Monroe have trouble controlling this desire, and do not like to go out on nights of the full moon.

Varying degrees of Woge
Woge can occur in different degrees, a higher degree of woge yielding a more complete transformation. One particular Wesen, the Jägerbar, has even been observed in a complete transformation into a grizzly bear after first removing her clothes.

Many Wesen have been observed partially transforming, and most known Wesen have been observed transforming only to a degree detectable by a Grimm. Blutbaden, Geiers, Coyotls, Drang-Zorns, Steinadlers, Raub-Kondors and Balams have demonstrated being able to shift partially by localizing the woge around their eyes. Blutbaden's eyes turn into a fiery red, Geier's eyes turn pure black, Drang-Zorn's turn green, Balam's eyes turn amber, and Coyotl's eyes glow bright yellow. Others have only partially woged before, such as Doug Shellow, a Mellifer, morphing only his arm.

There also appears to be a large degree of separation between the human and Wesen forms. One Klaustreich showed scars on his face in his Wesen form, clearly sustained during past fights, but he did not possess scars in his human form. A male Dämonfeuer also demonstrated this as his human face, but not his Wesen face, was badly damaged. A male Coyotl had a scar over the left side of his face and what appeared to be a blind right eye when woged but had none of these injuries while in human form. However, this may be true only for some Wesen, as Catherine Schade, who fought Kelly Burkhardt as a Hexenbiest, had large injuries on her human face after the fight and shortly before she died. Her Hexenbiest form however was not injured. Likewise Diane Rabe was severally injured in her Jägerbar form, and kept the injuries in her human form. This also doesn't apply if the wound in question is fatal.

Also, the fact that the injuries kept appearing when transforming suggests that injuries sustained when in one body doesn't have any effect on the other and that woge does not reset either the Wesen or Human forms and that injuries sustained are permanent.

On the other hand, it should also be noted that some species seem incapable of becoming totally human and their Wesen forms and abilities blur together with their human bodies to a greater or lesser degree. One such Wesen is the Siegbarste who retain their dense bone structure and high tolerance for pain even in their human form. Hexenbiests are also known to retain their marks upon their tongues at both human and Wesen forms. Many types of Wesen (namely canid Wesen and Bauerschwein) have shown to have enhanced senses without morphing, and Blutbaden have also consistently displayed inhuman strength while in their human forms. Spinnetods also retain their regenerative abilities despite being in human form. Dämonfeuer are able to breath fire, regardless of whether in human or Wesen form. Likewise Murciélago can use their sound attack, in either form. Skalenzahne, Hässlichen, and Dämonfeuers are still inhumanly strong while in their human forms. Ziegevolk pheromone tricks still work in human form.

Some Wesen can tell if their own is being truthful or not via their woge. Königschlanges can tell if someone is being truthful, or if they're dead because they can sense weak vibrations such as someone's pulse.

Wieder Wesen
Wieder Wesen are Wesen who have mastered control of their Woge. Wieder Wesen often adopt an almost entirely harmless lifestyle, either by choice or out of necessity.

For example, the Wieder Blutbad Monroe switched to a vegan diet to help himself avoid having to confront his Woge, while the Wieder Spinnetod Charlotte experiences the effects of rapid aging since she is unable to molt without consuming human entrails. She also refrains from wearing shiny things, because Spinnetoden are attracted to them and she is resisting her impulses. In addition Wieder Lausenschlange such as Quinn abstain from preying on Mauzhertzen, which allows both species to get along with one another, even to the point of friendship.

They may show signs of "giving in" by instinct, as seen when Monroe shifted into Blutbad form after seeing several kids dressed in red ride past him, but such impulses are often short-lived. Typically, they only succumb to their Woge for defensive purposes; and thus offer themselves an edge during confrontations.

Loss of Woge ability
In Hexenbiester, the ingestion of a Grimm's blood causes the Wesen within the individual to die, and the person is unable to woge into a Wesen form again, effectively rendering the person a normal human.

Woge retraction disorder
In some rare cases, a Wesen may not be able to retract or woge back following the transformation. Four such cases were caused by a sudden drop in supply from a subcutaneous drug pump that pumped homeopathic herbs, spices, and traces steroid amounts into the bloodstream of Wildermänner.

This was also accompanied by a wild rampage. This may be attributed to the Wesen developing a dependency on the drug that suppresses their woge, since after it ran out, they begin to exhibit dangerous symptoms.

Half-Wesen
It is possible for a human and a Wesen (such as a Hexenbiest) to have children, where the child is only a half-breed. When such individuals woge, they don't exhibit quite as many morphological changes as a full Wesen does.