Yavan, Symbi-Synthesis

At the beginning of each upkeep, create a 1/1 green Saproling creature token.
{w}, sacrifice a Saproling: You gain 1 life.
{b}, sacrifice a Saproling: Target creature gets -1/-1 until end of turn.
{r}, sacrifice a Saproling: It deals 1 damage to target player.
{g}, sacrifice a Saproling: Saprolings you control get +1/+1 until end of turn.