The current penguin sledding quest in Tiragarde Sound, alliance side (don’t know if it shows up horde side). If you are trying this quest and that stupid yeti keeps catching you, you are slowing down even if missing the snow piles, here is a tip.
Dismiss your pet. Although you don’t see the pet, it is there hitting snow piles and slowing you down anyways. Also, if your pet refuses to go away, kill a penguin or two and try again. I had to do all the above and the quest becomes very easy to do.