Sneasel was Silver's first Pokémon, that he has had with him since childhood, prior to his kidnapping from the Masked Man at age two.
It made its debut in the end of the first chapter, clinging onto the ceiling with Silver unseen, waiting to strike. He helps Silver to kidnap a Totodile, and fought off Gold's Aipom with Icy Wind. Throughout the series, he was has main battling Pokemon, alongside Totodile/Croconaw/Feraligatr.
He used it to battle the Masked Man, but his Pokemon were too elusive for Sneasel nor Exbo to hit them. He eventually is able to hit them with Icy Wind, but was crushed by their devastating attacks. Sneasel fought against Chuck's Hitmontop, but despite the 4X disadvantage, he held his own. Sneasel also fought against the Masked Man's Pokemon with Beat Up in a rematch, but the real battle lied in the hands of the 3 original Pokedexholders, alongside the 3 legendary birds.
It was also shown to have a good memory of Silver's past, and was used to coerce Silver into remembering it, through assistance from Yellow.
In the HeartGold/SoulSilver chapter, Silver was ambused by a mass off Koffing belonging to Team Rocket, but Sneasel evolved into a Weavile with a Razor Claw, and then defeated all of them with a single Icy Wind. Before evolving, Sneasel stole a plate from one of them, which he took and interest to. He was also used in the next chapter to fight the same mob of Koffig, who were to trying to poison him. He took them all out with another Icy Wind, and sealed the vents that were leaking the poisonous gas with the same move, as well as stealing 2 more of Petrel's plates. Weavile then was sent out to receive all 17 plates, and succeeds. He was also used against Arceus and the creation trio, and did damage to the 3 Dragon types with Icy Wind. He focuses an Assurance on Girintina, but is overwhelmed by the powerful legendaries.
It is at a whopping level 84, making it tied with Gold's Typlosion (Exbo) for the strongest Pokemon in the Gold/Silver/Crysatal arc (as none of Crystal's Pokemon have surpassed level 80). However, their levels are dwarved compared to Red's Pokémon, of which Saur and Pika surpass level 90, and the others are in the high 80's.
- In Viz Media volume 41, both Weavile and Honchkrow are referred to female while they referred male in the original volume.