From Bulbapedia, the community-driven Pokémon encyclopedia.
Samurai Sniper is the name of the deck used by Kabu Fukase, one of the semi-finalists of the Junior Division in the 2017 World Championships. It is one of the 2017 World Championships Decks, released November 17, 2017. Each deck comes with a Worlds 2017 deckbox, a booklet about the championships, a 2017 World Championships pin, and a code card for the Trading Card Game Online. The cards in this deck aren't the actual prints used in Fukase's deck, but are the most recent printing of the lowest rarity of the cards.
The popular Decidueye-GX deck got last one hurrah at Worlds before the essential Forest of Giant Plants rotated out, and Kabu Fukase gave it the best showing, achieving a Top 4 in the Junior Division! The addition of Golisopod-GX gives this Ability-focused deck a powerful attacker for the Active spot, while Decidueye-GX can keep to the shadows of the Bench and pick off the opposing team with Feather Arrow!
This year's Worlds marked Kabu's last season as a Junior Division player, and it was his last chance to play the card he finds most interesting, Forest of Giant Plants (which has now rotated out of the Standard format and is currently banned in Expanded). But he gave it an excellent send-off, finishing in the Top 4 of the Junior Division by pairing the popular sniper Decidueye-GX with the powerful new attacker Golisopod-GX. Kabu had one very specific concern going into the tournament: "I was worried that I might have to battle Tsubasa" Watanabe, another top player from Japan who was defeated in the Top 8.