Actually, competitively speaking, Snow Cloak is Mamoswines best ability. When you obtain a pokemon from the dream world to get its Dream World Ability, you cannot breed it to get egg moves. Mamoswine is a Pokemon that does rely on Egg moves. Icicle crash is much better than Ice fang, and Mammoswine loses out on Stealth Rock & Icicle Crash. Icicle Crash is stronger than the aforementioned Ice fang, and as well as Ice Shard. Stealth Rock can be used with a sash, and icicle crash can be used on more offensive sets. Although completely irrelevant, Mamoswine gains alot of useful moves from the HG SS move tutor.