If you're going to to make competitive, then the Standard Thick Fat sets found on most Piloswine won't be available. So, here's a moveset (For NU tier):
Defensive:
Piloswine (M) @ Eviolite
Trait: Snow Cloak
EVs: 252 HP / 4 Atk / 252 Def
Quirky Nature (get Impish if you can)
- Stealth Rock
- Ice Shard
- Earthquake
- Toxic
Offensive:
Piloswine (M) @ Eviolite / Choice Band
Trait: Snow Cloak
EVs: 252 HP / 252 Atk / 4 Spd
Quirky Nature (get Adamant if you can)
- Earthquake
- Icicle Crash
- Ice Shard
- Stone Edge / Superpower
RU Tier:
Tank:
Piloswine (M) @ Eviolite / Life Orb
Trait: Snow Cloak
EVs: 252 HP / 252 Atk / 4 Spd
Quirky Nature (get Adamant if you can)
- Earthquake
- Icicle Crash / Ice Fang
- Ice Shard
- Stone Edge / Stealth Rock
All movesets are from Smogon.
As you requested, Mamoswine:
OU:
Choice Band (To pick off Therian formes and Dragons) (Life Orb can be used too)
Mamoswine (M) @ Choice Band
Trait: Snow Cloak
EVs: 4 HP / 252 Atk / 252 Spd
Quirky Nature (get Adamant if you can)
- Ice Shard
- Icicle Crash / Ice Fang
- Earthquake
- Stone Edge
Stealth Rock lead:
Mamoswine (M) @ Focus Sash
Trait: Snow Cloak
EVs: 252 Atk / 4 Def / 252 Spd
Quirky Nature (get Adamant if you can)
- Ice Shard
- Stealth Rock
- Earthquake
- Endeavor / Superpower
Choice Scarf
Mamoswine (M) @ Focus Sash
Trait: Snow Cloak
EVs: 252 Atk / 4 Def / 252 Spd
Quirky Nature (get Jolly if you can)
- Icicle Crash / Icicle Spear / Ice Fang
- Stone Edge
- Earthquake
- Superpower
All movesets are from Smogon.