Crawling Infestation is a uncommon Enchantment card from Innistrad: Crimson Vow (VOW), collector number 193. Current market price: $0.24 (foil $0.37), TCGplayer market prices via Scryfall.
At the beginning of your upkeep, you may mill two cards. (You may put the top two cards of your library into your graveyard.) Whenever one or more creature cards are put into your graveyard from anywhere during your turn, create a 1/1 green Insect creature token. This ability triggers only once each turn.