The Marcus/Eiko stat bug is a bug which occurs when leveling Marcus in Final Fantasy IX causing some of Marcus's stat growth to be added to Eiko's without affecting her level, enabling her to obtain much higher stats. Eiko will not retain Marcus's level when she is obtained, but will inherit his stat growth. Eiko's level will be determined by the levels of the current party members: Zidane, Dagger, Vivi and Quina.