In the Santa Sleigh Event Update, the developers have added a new type of chest to the base game called the Abyssal Treasure. Unlike other treasures in the game, the Abyssal Chest provides a lot of items that are high in rarity and will help you roll for better pets and items in the game. So, here is a brief guide on how to get the Abyssal Treasure Chest pretty quickly.
To answer the burning question, you can get Abyssal Treasure Chest in PETS GO only through Ice Fishing. Yes, it is obtained randomly while you Ice Fish at the North Pole. To do this, you must unlock the Ice Fishing option, followed by the Abyssal Depth, inside the Holiday Event section of the Upgrade Menu. While Ice Fishing only costs a few Gingerbread Tokens, the Abyssal Depth needs 3 Million Gingerbread Tokens. So, farm a lot of gingerbread tokens through regular fishing and hitting all the breakables around you like the heap of Gingerbread Tokens.
Once everything is unlocked, you can start fishing for the Abyssal Treasure Chest from the Ice Fishing area at the center of the North Pole. While the Upgrade option allows you to start fishing for the item, you can increase your chance of getting the Abyssal Treasure using two ways - Abyssal Fishing Bait and Abyssal Treasure Chest Upgrades.
For the former, you can purchase it from the Forever Pack, while the Upgrades can be unlocked using the same Gingerbread Tokens from the Holiday Event Menu.
For more on Roblox PETS GO, check out Roblox PETS GO Fishing Guide – Merchant, Baits, Tokens and More, or How to get the Reindeer Cat Titanic Pet in PETS GO on Pro Game Guides.