This quest scales to the level tier of the character (i.e. level 21-30 characters will receive the level 25 version of the quest). You may need to kill more than the listed number of monsters in order to retrieve the required drops for this quest.
This article refers to events, personae and activities only present in-game during the annual Frostfell celebration. Frostfell comes to Norrath each year from (roughly) the second week of December to the first week of January.