Waterfiends frequently drop Crimson charms.
Charm Drop Rates
Waterfiends hit pretty high, and fairly often, so they're not very good training. They are weak against crush attacks. The best weapon to use is the Saradomin sword. It is also suggested to wear magic defence armour (Karils) and pray range while fighting these to have decent effect.
A fiendish embodiment of water.
Clue scroll (hard), Rune med helm, Starved ancient effigy
Water rune (1-91) (100%), Vial of water (noted) (5-10), Water talisman, Nature talisman, Mist rune (3-7), Death rune (9-18), noted Mithril ore (1-5), Mithril bar (2), Fishbowl, Wildbood seed, Staff of water, Water battlestaff, noted Water orb (3-10), Mithril warhammer, Grimy herbs, Mithril arrow (90), Raw shark (3-6), Shark, Lobster (12), Adamant chainbody, Jangerberry seed, Seaweed (1-27), Herb seeds, Strawberry seed, Watermelon seed (1-3), Blood rune (4-11), Steam rune (1-4) , Mud rune (3-5), Raw lobster (3-8), Whiteberry seed, Mushroom spore, Rune javelin (5), Snape grass (3-20), Sapphire bolts (15), Blue d'hide vambs, Mithril full helm, Gold charm, Green charm, Crimson charm, Blue charm