Waterfiends have a very high charm drop rate, especially for crimson charms, making them very popular among players training Summoning with them compared to other monsters. While the Ghorrock waterfiends have a halved rate for the charms, they drop two at a time, essentially making the rates the same.
They are weakest against crossbow bolts, making any form of ranged a good choice for killing them. They can also be killed with higher level magic weapons. Using darklight is a viable method for those wishing to use melee. The waterfiends at Ghorrock seem to be easier to hit, but also seem to deal more damage. At Ghorrock they are found on the lower floor after completing The Temple at Senntisten and are aggressive. When killing waterfiends, an elite version may spawn (guaranteed while on a Slayer assignment), which can be further increased with the use of fellstalk incense sticks.
This monster has access to the Wilderness shared loot table, which is a tertiary drop. To access the table, it has to be killed inside the Wilderness. Luck-enhancing items are not required to access the table, but do increase the chance of doing so, as does doing higher-level content.
Corrected the melee attack accuracy for the following NPCs: Dagannoth Mother, Dominion Tower Dagannoth Mother, Temple at Senntisten quest fiends and Cockatrices.
Waterfiends have an unannounced graphical update and drop table change with the release of Smoking Kills. Two subsequent system updates later that day fix bugs and change the drop table further.
Waterfiends used to drop un-noted quantities of raw lobster and raw shark because players would often use Bunyips to consume them when training there, but this was changed shortly after the launch of the Evolution of Combat.
^Mod Sponge. Need Help! creating kalgerion demon pouches does not work. Reddit. 11 August 2020. (Archived from the original on 21 January 2023.) Mod Sponge: "so this is actually part of how binding contracts work - each familiar also has a slayer requirement to catch them, that is equal to their summoning requirement."