Fiend
In D&D, a fiend is a negative supernatural entity.
The term is a bit weird, since D&D fiends are what we IRL would generally call a demon. D&D, however, makes a distinction between fiends and demons: fiends are the generic term for any evil spirit, whereas a demon is one specific type of fiend—specifically, a Chaotic Evil fiend.
Etymology
The word comes from the Middle English word for "enemy" or "demon," which comes from Old English feond ("enemy").
Types
Main
The three main types across both D&D and PF are devils, demons, and yugoloths (aka "daemons"). These three groups align with the three Evil alignments: devils are Lawful Evil, demons are Chaotic Evil, and yugoloths are Neutral Evil.
Basically, in ascending order of "how badly do you NOT want to run into one of these guys," it goes: devils, yugoloths, demons. Devils love a good deal; yugoloths are cruel and brutal but are far from erratic; while demons are batshit insane and will kill your entire fucking family if you so much as sneeze in their direction.
Other
There are other types or "species" of fiend in the multiverse.
D&D
- Barghest (NE).
- Demodand
- Demon (CE).
- Devil (LE).
- Hordling
- Kython
- Night hag (NE).
- Rakshasa (LE).
- Yugoloth (NE).
Pathfinder
- Asura (LE).
- Daemon (NE).
- Demodand (CE).
- Demon (CE).
- Devil (LE).
- Div (NE).
- Velstrac (LE).
- Oni (E).
- Qlippoth (CE).
- Rakshasa (LE).
- Sahkil (NE).
List
- Abraxas
- Asmodeus
- Choronzon
- Gremory
- Legion
- Thasaidon
