Dämonfeuer

A Dämonfeuer (alternate spelling Daemonfeuer; DAY-mon-foy-ər (Grimm: DAY-muhn-fyoo-ər); Germ. Dämon "demon" + Feuer "fire") is a dragon-like Wesen that was first seen in. They are among the rarer species of Wesen.

Fred Eberhart is inside an old warehouse, looking for more scrap copper to steal. When two other copper thieves break into the same warehouse, he follows them. Fred then fills the room with coughed up vapor, and sets it ablaze, engulfing the two thieves in a massive fireball. Fred flees the scene and is almost run over by a car doing so.

The driver that almost hit Fred comes to the precinct and describes Fred's appearance to the detective, describing the scraggly beard and scar across his face.

Fred later attacks the owner of the copper warehouse, trying to get to the copper. Nick, Hank and Wu enter the building, where Wu is sprayed by Eberhart's oily vapor. Nick and Hank rescue Wu just in time to dodge Fred's ignition of the vapor.

Nick and Hank later receive an ID giving them Fred's name. They also find that he is a homeless war veteran who used to work as a welder, and that he has a daughter named Ariel Eberhart, who works at a nightclub.

Nick later goes to the nightclub where Ariel works as a fire dancer, where he also finds Monroe. Monroe tells Nick about Dämonfeuers, dragon-like Wesen who can burn their fat to essentially breathe fire. Nick then questions Ariel, who tries to make advances on him, knowing he's a Grimm. Ariel tells him that after her mother died she fell out of contact with her father, who blamed himself for her mother's death.

Ariel later tackles Nick, who was investigating her home. She answers Nick's phone when she sees that Juliette was calling him. She makes it seem as if Nick was cheating on Juliette.

Hank and Nick later go back to Ariel's house, where they find that the property is covered on the inside with copper. Nick goes back home where he finds Ariel in his bed instead of Juliette. The Dämonfeuer reveals that she has kidnapped Juliette and coughs up her flammable vapor, forcing Nick to duck for cover and allowing herself to escape.

Ariel and Fred are later confronted by Nick and Monroe. While Nick fights Fred with a copper lance, Juliette breaks free of her bonds and knocks Ariel out, escaping the Dämonfeuer lair with Nick and Monroe. Ariel later finds a dying Fred, and circles around him while coughing up vapor. The cave entrance is then seen with a fireball erupting out of it, killing Fred and presumably Ariel.

However, Ariel is later seen walking out of the cave unscathed.

The Carnival Metamorphosia, a Wesen carnival, housed a performer named Damien. Damien went under the name of "Damien the Last Dragon" and would woge into his Dämonfeuer form while breathing fire into the audience. He covered up his true Wesen nature by displaying his form as if it were a magic trick.

After Hedig, the neglectful ringleader, runs away from the carnival after Max Robbins loses control of his Wesen side, Damien goes with Genvieve and Ivan, his fellow performers, to take revenge on Hedig. They corner him into a house of mirrors, and Damien kills him with a fireball.

Characteristics
When they woge, Dämonfeuer undergo one of the more extreme changes of any known Wesen. Their skin becomes a green and scaly hide, their nose becomes flat, their eyes take on a fire-like appearance, and most notably they grow a large crown of horns on their heads. Males possess a larger set of horns and have more angular faces than females. Despite rather extensive transformation, Dämonfeuer still retain physical traits of their humanity mainly their ears and hair which remain largely unchanged.

Dämonfeuer are much stronger than humans, and are at least as strong as Grimms. However like humans, their strength seems to more-or-less differ by gender. Their strength and durability seems to be greatly diminished in human form, since Juliette was able to knock Ariel down with one hit. This only seems to apply to females, though as Fred was able to fight Nick in his human form. Male Dämonfeuer are incredibly physically powerful, as the elderly and sickly Fred Eberhart was able to fight Nick on an equal level, and even knocked him down twice, despite Nick being much younger.

Fire and smoke production
The diet of Dämonfeuer consists mainly of humans. This fat-rich but low carb diet induces higher levels of gastric acid production, crucial for digestion within the stomach.

The production of too much gastric acid results in frequent heartburn. If the gastric acids spill into the lungs, this induces coughing, which is the body's way of ridding the lungs of the acids that settle in them.

Dämonfeuer take heartburn to a whole new level with their unique ability to convert fat through ketosis into a highly combustible acetone vapor, mixed in with the gastric juices that spill into the lungs, leading to laryngopharyngeal reflux. Thus, when a productive cough is expelled, the combustible vapor is sprayed from the mouth. Following a series of vapor-releasing coughs, a single productive cough releasing gastric juices from the lungs is enough to ignite the gas, and giving the appearance of fire expelled from the mouth.

This fiery breath causes anyone in its path extremely severe burning, and death to anyone who it hits. Their fire has been compared to napalm, in terms of heat and destruction, and is enough to melt metal and burn humans to a crisp in seconds. Dämonfeuer seem to have two forms of fire breath. The first and most used form is slowly releasing the vapor and after making the air thick with it, igniting the vapor. The other version is a quick flamethrower style attack, where the Dämonfeuer just opens it's mouth and breathes fire, like a typical dragon. They also seem to have a natural resistance to heat and fire. ;However, as Frank Eberhart's face had been burned in a house fire, it appears they are not totally invulnerable.

Behavior
Dämonfeuer are treasure-mongers although, in modern times, they have abandoned gold and jewels, instead collecting large amounts of copper of which they are very possessive. They have no qualms with stealing copper to increase their horde.

Due to their might, Dämonfeuer are not afraid of Grimms. Dämonfeuer also don't seem to harbor any hatred toward Grimms, despite the fact that Grimms have long hunted them. In fact, it appears Grimms are somewhat of a curiosity to Dämonfeuer, as Ariel Eberhart hinted that she had always wanted to see a Grimm up close.

Dämonfeuer, or at least male Dämonfeuer, seem to be a martial race, and have a value for combat, and see death from combat or in battle, as to die with honor and dignity. As such, they are commonly soldiers and sometimes war heroes. They also take pride from the memory of their relatives' services. For this is the reason they sometimes capture warrior’s lovers, so that the warrior would come to face them, and they would be able to fight to the death. Females also see this as an honorable death, although their idea of how they should die appears to differ. It is this which is the basis for the myths of dragon quests. This martial nature means that Damonfeuer are greatly ashamed when they fail to save their mates. Frank Eberhart was traumatized by the death of his wife, and his daughter, Ariel, was very disappointing in him, stating he should have protected her. The children of Dämonfeuer are always fiercely loyal to their parent, going to extreme lengths to help them and sometimes committing suicide upon the death of one. Dämonfeuer have a habit of making their lairs in caves.

Perhaps due to their nature, Damonfeuer are fond of occupations involving fire. Frank Eberhart was a welder, his daughter Ariel was a fire dancer, and his father wielded a flamethrower in World War II.

According to Monroe, the best way to fight them is with a lance. Guns can't be used, as they would ignite their vaporized fat, which would cause an explosion.

Excerpts from Grimm Diaries
In Aunt Marie's book, there is a story about a Dämonfeuer in medieval times.

Below are three excerpts taken from the journals:

The author of the latter story stated that the Dämonfeuer was the fiercest of them all.