Grown-up Snowball Fight is a special Battle card that is automatically placed in the center deck during the Santa Scramble event. A total of 4 copies are available per game, along with 4 copies of . Originally, these cards were added to the deck, giving the deck a total of 56 cards instead of the usual 48.. As of Version 1.31.4, they will instead replace two cards from each player's deck, keeping the deck at the usual 48 cards. Grown-up Snowball Fight is unique in that although it is listed as a Battle card, it is used only in snowball fights rather than battles.
- Although 4 copies of the card are put in the deck and it cannot be decked by the player, Grown-up Snowball Fight's description lists it as a Max 1 copy limit card. This is most likely because, after the replacement of the 2 cards, each player will have 8 cards that they chose, 1 , and 1 Grown-up Snowball Fight, following the Max 1 restriction.
- Confirmed by Rive on Discord.