Lattice Library is a rare Enchantment card from Secrets of Strixhaven Commander (SOC), collector number 40. Current market price: $0.24, TCGplayer market prices via Scryfall.
This enchantment enters with X study counters on it. When this enchantment enters and whenever you cast your first spell with {X} in its mana cost each turn, create a 0/0 green and blue Fractal creature token. Put a number of +1/+1 counters on it equal to the number of study counters on this enchantment.