The Animal Crossing New Horizons free update is coming on February 25, Super Mario themed items will be added, and all those new acnh items will be available in Nook Shopping starting 3/1. When the game is updated, you can buy these acnh Mario items from ACNHKK.com.
The following items have been confirmed to be in the update:
1-Up Mushroom
Block
Coin
Fire Flower
Floating Block
Goal Pole
Large Mushroom Platform
Pipe
Shell
Small Mushroom Platform
Super Mushroom
Super Star
Thwomp
? Block
Luigi Hat
Mario Hat
Princess Peach Crown
Wario Hat
Luigi 'Stache
Mario 'Stache
Wario 'Stache
Luigi Outfit
Mario Outfit
Princess Peach Dress
Wario Outfit
Luigi Shoes
Mario Shoes
Princess Peach Shoes
Wario Shoes
Mushroom Mural
Block Flooring
Lakitu's Cloud Rug
Yoshi's Egg Rug
Article Source: https://www.acnhkk.com/Super-Mario-themed-furniture-and-New-items-are-coming-to-ACNH-on-February-25th-article-237.html