Explosive Growth is a common Instant card from Invasion (INV), collector number 187. Current market price: $0.07 (foil $0.45), TCGplayer market prices via Scryfall.
Kicker {5} (You may pay an additional {5} as you cast this spell.) Target creature gets +2/+2 until end of turn. If this spell was kicked, that creature gets +5/+5 until end of turn instead.