To celebrate the Year of the Snake, players of the Chinese version of Pokémon Let's Go! Pikachu and Pokémon: Let's Go! Eevee can receive a Shiny Arbok from January 29th, 2025 until February 12th, 2025.

The code is: G0NGX1FACA1

Happy New Year to all Trainers and good fortune!
From now until February 12th, 2025 at 23:59 in Pokémon Let's Go! Pikachu and Pokémon: Let's Go! Eevee, you can get a Shiny Arbok by selecting Mystery Gift → Get with Code/Password in the game menu, and entering the code to receive it.

祝各位训练家新年快乐，恭喜发财！
快来《宝可梦 走吧！皮卡丘》与《宝可梦 走吧！伊布》中领取你的异色阿柏怪吧！
即日起至2月12日23点59分，在游戏菜单中选择“神秘礼物”→“通过序列号/密语接收”，输入密语即可领取。 ​​​

Source: https://weibo.com/6305628151/PbMqcgc2p