Demons are grouped together into several categories. The kanji 「系」(「けい」?; kei), at the end of each category's Japanese name means "group" or "lineage". Most of them are yōkai (「妖怪」?), a class of supernatural monsters in Japanese folklore.
Some of the bosses and sub-bosses have also been added to the list as noted.
Fallen Demons (「天邪鬼系」?; amanojaku-kei; heavenly evil spirit) are humanoid demons that commonly appear in Demon Scrolls and Devil gates throughout Nippon. Among these Fallen Demons, there are four subcategories (Imps, Guardians, Namahage, and Clay army); there are also five different general types that are consistently color-coded across all four families to indicate their order of introduction within the game, as well as their particular combat styles and methods of stunning them.
- The first green color code is the very weak but agile demons (Green imp, normal Namahage and Clay Soldier. The Guardian family doesn't have one of these).
- Then the red color code is the slightly stronger version which has a weapon, which can be used to hit, be thrown of used as a mean of defense (Red imp, Headless guardian, Blade Namahage and Clay Samurai).
- The yellow color code is a large demon which wields a large barrel or drum-like object and tunnels underground, only vulnerable when they surface (Yellow imp, Bell guardian, Bucket Namahage and Clay Drummer).
- There is a demon type that flies and can fire projectiles from the air (Blue imp, Halo guardian, Umbrella Namahage and Clay Flyer).
- Finally there is a demon type that can kick Amaterasu if she gets too close; they also wields four heads which can fire lasers and turn into projectiles (Black imp, Executioner guardian, Cannon Namahage and Clay Shogun). These heads can also cause explosions.
Ōkamiden has a similarly color-coded set of Baby Imps. The attack/defense patterns are, however, are inconsistent with the Imps of the original game.
An amanojaku is a small oni that can bring out the evil thoughts and desires hidden inside a person.
Namahage (「生剥」?; blister), refers to a ceremony observed in northern Japan during New Year's Eve, when men dressed as namahage scare disobedient children or else, they would put them into a bucket and drag them off to the snow covered mountains.
Demons in the Chimera Family (「鵺系」?; nue-kei) are large, four-legged creatures with a bulbous, armored body and a long tail. When first encountered, they stand on the ground, but they are capable of hurling large round projectiles across the arena and launching into short flights to attack from the air. They have a stunned state that immobilizes them on the ground and opens their armor, exposing their vulnerable cores.
Ōkamiden has at least two demons of this type: the Bone Clam and the Demon Nut. These demons, alongside the Chimera from Ōkami are the demons of this category that are not completely invulnerable to damage prior to being stunned; however, the demons in Ōkamiden are immune to attacks of the Celestial Brush until they recover from being stunned and started running around, tossing projectiles erratically.
A nue is a chimeric Japanese demon whose most common description (monkey head, tanuki body, tiger legs, and a snake for a tail) matches fairly closely with the Chimera proper within the game; the latter's body resembles a kettle of boiling water, consistent with a common folktale about a mischievous tanuki transforming itself into a teakettle.
Flying Demons (「烏天狗系」?; karasu-tengu-kei; Crow Tengu) are shaped like human-sized animals that stand upright on two legs (or fins). They are capable of staying airborne for long periods of time and hurling down flat projectiles in boomerang-like arcs, but can also attack from the ground.
At the end of the first playthrough of Ōkami, the game unlocks an "Presents from Issun" folder with Demon Concept Art. After the Crow Tengu, there is a piece of artwork depicting the Five Headed Dragon, which did not appear in the original Ōkami game. Its wings and katana suggest it as a more challenging Ubume which might have been intended for Kamui, the only place in the game with no Flying Demons. Since in this family, each demon's defense is broken by the previous member's Floral Finisher , the dragon's defense might have been breakable with Veil of Mist .
In Ōkamiden, the Snake Sash bears resemblances to the Five Headed Dragon, specifically its flight ability and katana. It is most likely that the Snake Sash is a redeveloped Five Headed Dragon.
Wheeled Destruction and Doom Mirrors
Wheeled Destruction (「輪入道系」?; wanyūdō-kei; "wheel entrance road" or "wheel priest") are circular demons in the form of oxcart wheels or round hand mirrors with elemental attacks. They have several distinctive forms of motion: rolling quickly around the edge of the combat arena, spinning like a coin in a straight path toward the center of the arena, or a helicopter-like overhead horizontal spin that drops down onto Amaterasu.
There are two families of wheel demons in Ōkami the Wheeled Destruction proper and the Doom Mirror - as well as the rare Poltergeist, which is actually a group of three weasels that can move as one.
Ōkamiden has a class of round, spinning children top demons that could be classified as "Baby Wheels".
Traditionally, wanyūdō refers to a tormented soul trapped within the burning wheel of an oxcart.
Greater Goblins (「大天狗系」?; Ōtengu-kei; Great Tengu) are large, winged demons that remain permanently airborne. They have melee weapons and a variety of ranged elemental attacks, as well as a "chaos mode" that makes them invulnerable and even more deadly until quelled by the proper Celestial Brush techniques. There are two different types of Greater Goblins: the Blue Cyclops and the Great Tengu.
The Great Tengu's weakness references a long standing belief in that a tengu training under melting ice or falling water would grant mystical abilities.
Although they are fought differently, the fact that they are large, permanently airborne demons and are invulnerable in the air may draw similarities of Lechku & Nechku to this category.
The Crab or Ichiro family (「一朗丸系」?; Ichirōmaru-kei) of demons has three members. Ichiro proper is the shark-like composite formed by the union of Jiro and Saburo. The latter two resemble a pair of hermit crabs and always appear together. Jiro flings sea urchins while Saburo digs into the floor of the combat arena until it floods with water.
Ichiromaru is the complete name of the Ichiro shark in the Japanese version of the game; -maru was once a common suffix for the names of treasured possessions, such as ships or sons. Ichiro was a customary name for a firstborn son, as Jiro and Saburo were customary for the second and third sons respectively.
Isonade are said to be vicious, violent sharks that would swim near boats and pummel unsuspecting fishermen into the sea with their huge, club like tails, where they could feast on them.
The Bovine Demons (「牛頭鬼系」?; gozuki-kei; ox-headed oni) are large, powerful, and four-legged demons whose mask-like shields make them initially invulnerable to frontal attack. They have several attacks: melee weapon strikes, a ranged elemental attack on the ground, a brute-force charge straight forward, or a crushing aerial plunge. To effectively attack them, Amaterasu must get behind to strike at their unprotected posteriors; it is also possible to destroy their shields, leaving them vulnerable from all angles.
The gozuki is often paired with the mezuki (「馬頭鬼」?; horse-headed oni) in the phrase "gozu-mezu", referring to the pair of gatekeepers of Hell in Buddhist mythology. The Fire Beast, Ice Beast, Spark Beast, and Death Beast in Ōkamiden may possibly refer to the Mezu.
The Ōkami Official Complete Works lists the Tube Foxes as the sole member of Canine (「狗系」?; inu-kei; dog), but the Eight Canine Warriors also qualify. The Tube Foxes in the Water Dragon and the individual Canine Warrior fights are all sub-boss fights. The only other place where the Tube Foxes appear are in the North Ryoshima Coast Devil gate trial cave; there is also an optional group rematch against the Eight Canine Warriors. The second half of the miniboss Oki's battle and the boss Ninetails may also fit into this category, although the latter breaks up into multiple Humanoid-type demons during the match. However, when 8 tails are destroyed and Ninetails reveals her true form, she is fought in the same way as other canines.
The Ōkami Official Complete Works lists Bandit spiders as the sole member of the Arachnid category (「蜘蛛系」?; gumo-kei; spider), but they are very similar to (and slightly more difficult than) the Spider Queen boss. There are also several different types of Spiders (Blocking Spiders, Platform Spiders and Flame Spiders) but those are barrier creatures that cannot be fought in a conventional way.
In Japanese myth, spiders are seen to be demons in disguise during the day, and proficient users of magic as well, symbolized by their webs. The Tsuchigumo, were said to be gigantic spiders that lived in the mountains.
"Tsuchigumo" would be also used as a derogatory term for bandits and thieves, akin to the fact that they lived in the forest, under the ground and in caves.
The Ōkami Official Complete Works lists the Dogu as the sole member of the Humanoid category (「人型系」?; hitokata-kei; human-shaped) but several sub-bosses also qualify: Waka, Evil Rao, Oki (in the first half of his battle), and Nagi. All of them initially appear to be armed with a sword for hand-to-hand combat, but they also have aerial flying-blade attacks (countered with Power Slash) and swift forward charges. The boss Blight may also fit into this category.
Although not classified together in the Ōkami Official Complete Works, barrier creatures are various opponents whose attacks do not create a separate battle arena. Most of them cannot be defeated by normal methods.
- Tyrannosaurus - like beings can be seen in early concepts, but were categorized as monsters.
Symbolic appearances and thematic importance
Within the series, much like the the feature of a story, the appearance of demons come to also highlight aspects central to the plot which the story is taking place in. This is especially noted in Okami proper, as different areas of Nippon host different demons significant of their chapter.
- Middle Nippon, featuring Shinshu Field, Agata Forest, and Taka Pass, has their demons come to represent the basest of supernatural evil coming to harass and torment the living. Represented strongly by Orochi, their ilk helps symbolize chaotic malevolent and harmful forces at work that plague mankind, being from the incarnations of disaster, tragedy, and disease, to the mighty imposing over those less able to defend themselves.
- Southern Nippon, featuring the Ryoshima Coast, helps represent social themes and civilization, as to their demons. Rather than strictly demons representative of calamity and chaos, their demons hold themes of mortal souls corrupted by their lives into ways of evil and depravity, and given reincarnation as demons fitting for their consequences. Many of their inspirations are strongly derived from Buddhism and its lexicon of demons and morality, heavy with themes of karma, deception, and torment.
- Northern Nippon, featuring the island of Kamui, helps represent the unknown. With a land unlike most of Nippon, Kamui shares themes of the fantastical, the otherworldly, and the other side of nature which makes reality not seem real. With their demons, they come to represent conceptual and abstract manifestations of dangers in its cold and extreme realm, evocative of the use of symbolism within folkloric religions like that of Ainu religion to describe taboos and evils to avoid.
- Name given in the Ōkami Official Complete Works