Moseo, Vein's New Dean (SOS #091)

Flying

When Moseo enters, create a 1/1 black and green Pest creature token with “Whenever this token attacks, you gain 1 life.”

Infusion — At the beginning of your end step, if you gained life this turn, return up to one target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this turn.