Mythos of Illuna is a rare Sorcery card from Ikoria: Lair of Behemoths (IKO), collector number 58. Current market price: $0.22 (foil $0.32), TCGplayer market prices via Scryfall.
Create a token that's a copy of target permanent. If {R}{G} was spent to cast this spell, instead create a token that's a copy of that permanent, except the token has "When this token enters, if it's a creature, it fights up to one target creature you don't control."