A Rat's tail is a quest item used in the Witch's Potion quest. It can be obtained by killing any rat in RuneScape after the player has begun Witch's Potion. The item has a 100% chance to drop once you begin the quest.
After completion of the quest, the Rat's tail is unobtainable unless you kill a rat, complete the quest and then pick it up. If the player shows a Rat's Tail to the Wise Old Man after completing the miniquest, he will tell the player to get rid of it. (Before completing he says "You have brought me a tail of a rat!" and "Yes, I think you should keep it for now.")
Monster Combat level Quantity Rarity Rat 1 1