Flumphs also glowed faintly in different colors depending on their mood:
- Pink: amusement
- Blue: sadness
- Green: curiosity
- Red: anger
Flumphs were wise and possessed advanced knowledge of philosophy and other subjects. They fed on psionic energy and were therefore more likely to be found near strong sources, such as aboleth, gith, and mind flayer settlements. However, due to their strong telepathic nature, flumphs were very sensitive to evil thoughts and felt the need to share them as quickly as possible with any good-aligned creatures they found, in order to wash these thoughts away.
Normally, a flumph's reaction when facing an evil creature was to flee. However, flumphs' tendrils were acidic and could be used as defensive weapons if necessary.
Flumph society was organized in harmonious cooperative groups called "cloisters", in which all flumphs contributed according to their own skills. They were also known for sometimes recruiting isolated mindwitnesses into their communities. Once a mindwitness was taken in service of the flumphs, it would change its world view accordingly and was no longer an evil creature.
The origin of the flumphs was ultimately a mystery. It was speculated that flumphs were genetically related to grells or belabras, due to some physiological similarities such as their hovering and the presence of tentacles. Given the probable genetic ties to the grells, most sages agreed that flumphs originated in a different world and traveled as clandestine passengers in grell spelljammer ships.
During the late 1480s DR, flumphs were greatly disturbed by the demonic madness that permeated the Underdark. Some offered assistance to anyone who opposed the derro cultists under Gracklstugh, while a cloister of flumphs from the Wormwrithings maintained that kindness was the only appropriate response during those evil times. 
- Laal, an erudite female flumph who contacted a group of adventurers to seek justice for the murder of her mate, Xol;
- Xol, an adventurous male flumph who was murdered by the Cult of the Crushing Wave in an expedition to Mulmaster's sewers.
- ↑ 1.0 1.1 1.2 Jon Pickens ed. (1995). Monstrous Compendium Annual Volume Two. (TSR, Inc.), p. 58. ISBN 0-7869-0199-3.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Wizards RPG Team (2014). Monster Manual 5th edition. (Wizards of the Coast), p. 135. ISBN 978-0786965614.
- ↑ Logan Bonner, Chris Sims (April 2009). Dungeon Delve: Fool's Grove (PDF) p. 8. Wizards of the Coast. Retrieved on 2016-12-07.
- ↑ 4.0 4.1 4.2 4.3 Tim Hitchcock (January 2005). “Box of Flumph”. In Erik Mona ed. Dungeon #118 (Paizo Publishing, LLC), pp. 30–31.
- ↑ Don Turnbull (1981). Fiend Folio. (TSR Hobbies), p. 39. ISBN 0-9356-9621-0.
- ↑ Johnathan M. Richards (April 1998). “The Ecology of the Flumph”. In Dave Gross ed. Dragon #246 (TSR, Inc.), p. 78.
- ↑ Wizards RPG Team (2016). Volo's Guide to Monsters. (Wizards of the Coast), p. 176. ISBN 978-0786966011.
- ↑ Johnathan M. Richards (April 1998). “The Ecology of the Flumph”. In Dave Gross ed. Dragon #246 (TSR, Inc.), p. 81.
- ↑ 9.0 9.1 Christopher Perkins, Adam Lee, Richard Whitters (September 1, 2015). Out of the Abyss. In Jeremy Crawford ed. (Wizards of the Coast), pp. 67,167. ISBN 978-0-7869-6581-6.
- ↑ 10.0 10.1 10.2 Tim Eagon (2015-06-01). D&D Adventurers League: Foulness Beneath Mulmaster (DDEX2-08) (PDF). Elemental Evil p. 5, 10. Wizards of the Coast. Retrieved on 2016-12-07.