Fiend

In Quake, a Fiend or Demon (as called in the model files, such as demon.mdl) is a four-legged, monkey-like beast that uses its claws to slash a target. In addition, it is very fast and can leap great distances. Fiends stand approximately 6 feet tall (their back rises above their head) and have a muscular appearance.

Fiends have dark beige, adrenaline-flushed skin and a mouth full of sharp teeth. They also have two horn-like appendages growing from out of their head, and the area around their mouth is soaked with blood. Their hands are simply large, curved claws. They have long hind legs to leap with and feet that are large flat hooves. If they are stationary, they are crouched into a ball which makes them difficult to see if the player is in a hurry.

In combat, Fiends make an odd snarling noise and charge at an alarming speed towards their prey. They appear to have hooves for feet and powerful legs and haunches which allow them to jump great distances, and which can cause significant harm to anyone unfortunate enough to make contact with their leap. When they get close enough, they roar loudly and leap to point-blank range, slashing away with their claws. When they are killed, Fiends give out a low growl.

Strategies

 * Even alone, the Fiend is a very powerful monster. Its leaping attack allows it to traverse great distances and get over chasms quickly, and can inflict a significant amount of damage. The best way to evade its jump attack is by constantly circle-strafing so that it will miss you. Avoid getting too close to it, as its attacks become extremely difficult to avoid from a short range. Alternatively, find a corner or a low doorway between yourself and the Fiend so that its jump attack will be intersected. After that, it can be taken down without any issues.
 * If the Fiend's leap attack happens to land on the TOP of the player or a monster, its damage would be multiplied by many times, causing hundreds of damage, often gibbing the player with 250 health and 200 armor or killing a shambler with a single hit.
 * You can also potentially use the Fiend's leap attack to trick it into a trap - put yourself between the Fiend and an area in which the Fiend will be unable to reach you (i.e. a pit), and when it jumps, dodge the attack. If successful, the Fiend will fall and wind up stuck, allowing you to either kill or ignore it.
 * Avoid using explosives against the Fiend in close combat, as it frequently lunges towards you before the rocket makes impact, thus inflicting you with splash damage. Instead the Double-Barrelled Shotgun is useful as long as you use circle-strafing techniques. The Super Nailgun is effective against the Fiend at all distances as long as you have enough ammo. The Nailgun and Shotgun have some limited use for sniping a Fiend at medium ranges but won't inflict enough damage to quickly take down a Fiend in close range.
 * From a safe distance, both the Grenade and Rocket Launcher can take out a Fiend in three or four shots, if it happens to be a group of Fiends in a place in which they're unable to touch you, you can drop some Grenades down from a safe distance making it so they can bounce back into the Fiends if necessary. The Rocket Launcher in those circumstances is not advisable due to risk of Splash Damage.
 * While under the effects of the Quad Damage, any weapon can kill a Fiend in a few shots, although explosives are mostly single kill, it is pontentially dangerous to do so if the player isn't aware of the Fiend's movements. Take out either your Shotgun or Double-Barrelled Shotgun if you wish to save ammo, if it happens to be a group take out your Nailgun or Super Nailgun and fire away, they should be done in no time.
 * In a group of Enemies, the Fiend should generally be one of the first to go. Its movements are so swift, your focus will likely be vested in strafing away from its jumping attacks, which could distract you from other nearby monsters. Try to lure it into an area where there are no other enemies, which is easy given the speed at which a Fiend will pursue you.
 * A Fiend can cause a monster In-fight if its leap attack is intersected. Whether through its own doing or coming into another enemy's line of fire, provoking a Fiend in full health is a useful strategy, as it can take out almost any other creature (with the exception of a Shambler at full health or a Zombie) while sustaining massive damage to its own health for saving your ammunition.
 * The Fiend can still injure a player, even if both are on opposite sides of a wall, when using the claw attack. Oftentimes, the Fiend can be tempted to continue swiping after the player has hidden behind the wall, resulting in the player taking damage even though an obstacle exists between him and the Monster.

Death Messages

 * "Player" was eviscerated by a Fiend

Appearances

 * E1M2: Castle of the Damned
 * E1M3: The Necropolis
 * E1M4: The Grisly Grotto (Hard/Nightmare)
 * E1M5: Gloom Keep
 * E1M6: The Door to Chthon (Normal)
 * E2M2: The Ogre Citadel
 * E2M3: The Crypt of Decay
 * E2M4: The Ebon Fortress
 * E2M5: the Wizard's Manse
 * E2M6: the Dismal Oubliette
 * E2M7: The Underearth
 * E3M2: The Vaults of Zin
 * E3M3: The Tomb of Terror
 * E3M4: Satan's Dark Delight (Normal)
 * E3M5: The Wind Tunnels
 * E3M6: Chambers of Torment
 * E3M7: The Haunted Halls
 * E4M3: The Elder God Shrine
 * E4M4: The Palace of Hate
 * E4M5: Hell's Atrium
 * E4M6: The Pain Maze
 * E4M7: Azure Agony
 * E4M8: The Nameless City
 * E5M3: The Dark Days
 * E5M4: The Catacombs
 * E5M5: The Stronghold

Trivia

 * According to John Romero, fiends lack eyes because the fantastic realms that they’re native to are dim, humid, and horrific, thus eyes would be unnecessary.
 * The fiend is similar to a creature from H.P. Lovecraft's Cthulhu Mythos known as a Ghast.
 * GameSpot ranked the fiend as one of the best enemies for games released in the 1990s, due to its mobility.