Weavile

From the Pokémon Encyclopedia

Weavile is a 4th generation Pokemon that is the evolved form of Sneasel. It is a Dark/Ice type Pokemon, and may be seen in both the Pokemon: Advanced Battle theme song, and the eighth movie, Pokemon: Lucario and the Mystery of Mew. Being a Dark/Ice-type with high Attack and impressive Speed stat (Jolly Nature with Choice Scarf equipped allows it to outspeed many things), it is a powerful Pokemon with its Night Slash and Ice Punch attack. Sneasel will evolve into Weavile if it is holding a Razor Claw and levels up at night.