In this world there are Greater Demons and plain old mean demons. No one has ever encountered a demon who was actually trying to help.

Lesser Demons:

• Ahiab Demon- A massive scaled demon with a thick, lizard-like body. It's blind and has a keen sense of smell. A thick line of serrated teeth run along its forehead where eyes should be. It has another mouth on the lower half of its face as well, fanged with dripping tusks. It has a narrow tail that glitters as it moves due to it being edged with razor-sharp lines of bone. It has talons and a long, forked tongue with a bulb at the end of it like a scorpion's stinger. It rapes his victims before killing them.
• Behemoth Demon- It is formless, huge and slimy. A double row of teeth runs along the length of its oblong body. It slithers with an oozing, boneless motion. It eats anything and everything - people included. It can teleport and its mucus turns seraph blades ineffective. It is semi-corporal and very hard to kill. It can heal its wounds but it seeps its energy - the best way to kill it is to keep wounding it until it can no longer heal itself. Clarissa Fray describes it as "a blind slug with teeth". It creates low noises like angry insectile chittering when angered and when it is killed it leaves behind a puddle of steaming green fluid.
• Croucher Demon- Its poison is not life-endangering.
• Drevak Demon- It is blind and tracks by smell. They smell rotten, like garbage and are incredibly fast. This demon is not a figher, it is mainly used as a spy or a messenger (implying it is capable of human speech). It does not suck its victim's blood. Drevak demons don't have teeth, they have poisonous black spines in their mouths. Drevak poison is incredibly painful and poisonous and should be dealt with by a warlock. A Devrak attack is called a "Devrak sting".
• Eidolon Demon- it has the ability to shape-shift.
• Hydra Demon- Has several heads,hard to kill and usually used a sort of guard dog Iblis Demon - human-shaped but formed of a substance like coiling black smoke and a pair of burning yellow eyes. It likes to surround its prey but is not very bright. It bursts into ash when it dies.
• Kuri Demon- Slinking and black.
• Moloch Demon- likes to fight in groups. It has claws and jets flame from its empty eyes.
• Oni Demon- has a green body, wide mouth, and horns (sharp tusks sprouting from its forehead). It has legs like tree branches and spade-like hands. It is smart.
• Raum Demon- Dead white with scaled skin, a black hole for a mouth, bulging toad-like eyes, and arms that end in tentacles where hands should be. The tentacles are grey-white and tipped with blood-red suckers. Inside each sucker is a cluster of needle-sharp teeth. It has black blood and is poisonous. It is more dangerous than a Devrak demon and is incredibly fast.
• Ravener Demon- A long, scaled demon with a cluster of eyes set dead center in the front of its domed skull. It is something like a cross between an Alligator and a centipede with a thick flat snout and a barbed tail that whips from side to side. It has multiple legs and claws as well as a row of fanged teeth. He drools green fluid and is extremely slimy and poisonous. It can hang off of walls and has a long black tongue.
• Scorprios Demon- has a wrinkled face, the agile hands of a huge monkey but the long, barbed tail of a scorpion. Its eyes are rolling and yellow and it has teeth like broken needles. It hisses. It is incredibly fast and very poisonous. It uses its scorpion-like tail as a weapon.
• Shax Demon- has pincers and an insect-like carapce. They are brood parasites, who bring their victims back to their lairs in order to lay eggs in them while they are still alive. They also have a sharp sense of smell, and can be used for tracking.
• Spider Demon- has eight pincer-tipped arms and poison-dripping fangs that protrude from its eye sockets. It sprays acidic poison.

Greater Demons:

• Abbadon, Demon of the Abyss (Greater Demon)- Its flesh is livid and bruised looking. Through the seeping skin bones protrude - not new white bones, but bones that look as if they had been on this earth for a thousand years, black, cracked and filthy. Its fingers are stripped and skeletal, its thin-fleshed arms pocked with dripping black sores through which more yellowing bone is visible. It has taloned fingers and is at least 9 feet tall. It has empty eye sockets, smells bad and has 2 rows of jagged glass-sharp teeth. Its hide is grey with things seemingly crawling inside of it. He's faster than shadowhunters. It has hands and a mishapen head.
• Agramon, Demon of Fear (Greater Demon)- Shape-shifts into a person's greatest fear and literally scares its victims to death. When "formless" he is a black cloud with glowing eyes, a malformed, enormous, hideous shape with eyes the size of saucers.