Swinub locations — where to catch

In Kitakami (Scarlet & Violet – The Teal Mask)

• Chilling Waterhead — Walk
• Dreaded Den — Walk
• Fellhorn Gorge — Walk
• Kitakami Road — Walk
• Mossfell Confluence — Walk
• Oni Mountain — Walk
• Oni's Maw — Walk
• Reveler's Road — Walk

In Hisui (Legends: Arceus)

• Arena's Approach — Walk
• Avalanche Slopes — Walk
• Avalugg's Legacy — Walk
• Bonechill Wastes — Walk

In Sinnoh (Diamond, Pearl & Platinum)

• Acuity Lakefront — Walk
• Route 217 — Walk

In Johto & Kanto (HeartGold & SoulSilver)

• Ice Path — Walk

In Sevii Islands (FireRed & LeafGreen)

• Icefall Cave — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Ice Path — Walk

Other games (5)

• Brilliant Diamond / Shining Pearl (Gen 8): Route 217
• Sword / Shield (Gen 8): Dusty Bowl, Giant's Mirror, Giant's Seat, Hammerlocke Hills, Rolling Fields, Stony Wilderness
• Ultra Sun / Ultra Moon (Gen 7): Tapu Village
• Sun / Moon (Gen 7): Tapu Village
• XD (Gen 3): Phenac City

Swinub — full Pokédex entry