Snowshoe Hare
From Yarlyn Amberstill. With the extra large surface area of their legs, snowshoe hares are able to effortlessly hop along the snow while their pursuers get bogged down in... Critter type. I have captured just about every pet in the game as rare so I believe I have a pretty good knowledge of capturing pets.
The Snowshoe Hare is a wild battle pet found in Eastern Kingdoms, most reliably encountered as a secondary pet in battles fought around the Dalaran Crater in Hillsbrad Foothills and the Strahnbrad area of Alterac Mountains.
Guide awaiting review
Farm Dalaran Crater Battles
Head to the Dalaran Crater in Hillsbrad Foothills and engage wild pets such as Rats and Lofty Librams. Snowshoe Hares appear frequently as secondary pets in these battles, with multiple uncommon-quality sightings reported here.
Try Strahnbrad As Backup
If the Dalaran Crater isn't producing results, circle around the Ruins of Alterac into Strahnbrad, where Snowshoe Hares have been found as a secondary pet. Note that only 3 active battle pets can be up or queued at any one time in the Alterac Mountains area, including Strahnbrad, and a defeated pet will not respawn in the same spot for roughly 5 minutes.
Purchase From Yarlyn Amberstill
If you prefer to skip the wild capture process entirely, Yarlyn Amberstill sells the Snowshoe Hare at 70.4, 48.4 in Dun Morogh.
Tips
Snowshoe Hares can spawn as either a Battle Pet or a Critter — only the Battle Pet version can be captured, so not every hare you see will be engageable.