Nail beast nails are used to make Sanfew serums. The only source of these nails are nail beasts. A nail beast hits 3 times per attack, so one can be very dangerous. Nail beasts come in groups of 2-6 during a random encounter in the Temple Trekking minigame.
Dropping monsters
Monster Combat level Quantity Rarity Nail beast 69; 98; 141 1 Always