“Marcia Chase in Dalaran City wants you to bring her 5 Bloodtooth Frenzies.”
Travel to Borean Tundra in southwestern Northrend. When there simply kill any beast near a body of water such as a Mammoth or Marsh Caribou. After doing so you will turn red signifying that you have been covered in the animal’s blood. Jump quickly into a nearby body of water. Do not jump too far off shore as the spot you jump into is also where the Bloodtooth Frenzy pool will be located. You will then need to equip a fishing pole and fish this red pool you have created. Once you fish up five Bloodtooth Frenzies from the pool travel back to Marcia Chase to turn in and complete the quest.