They can retreat and other Wallasalki's in the area will attack you instead. Once they flee they will not re-attack you if you attack them.
Wear armour that boosts your ranged stats and protects against magic, as Wallasalki's cast water wave. Attack them using a ranged attack as they are weak against range.
A fearsome magical water creature.
Clue scroll (level-2), Starved Ancient Effigy
Bones (100%), noted Rune essence (5), noted Pure essence (2-9), Fibula piece, Ribcage piece, Skull piece, Skeletal gloves, Skeletal boots, Fire talisman, Water talisman, Earth talisman, Air talisman, Body talisman, Mind talisman, Chaos talisman, Nature talisman, Water rune (3-6), Air rune (1), Mind rune (1-4), Earth rune (3-12), Chaos rune (8-10), Death rune (8), Blood rune (5), Raw herring, Raw tuna, Raw mackerel, Steel arrow (1-7), Grimy herbs, Blue charm, Crimson charm, Green charm, Gold charm