Leonore, the Herbal Witch

{1}{g}, {t}: If target creature has no +1/+1 counter on it, put a +1/+1 counter on it.
{1}{b}, {t}: If target creature has no -1/-1 counter on it, put a -1/-1 counter on it.
"We wouldn't have a chance without their mixtures."
-Captain Jasper