Granny Groo is grandmother of Groo and Grooella. In stark contrast to her stupid grandson, Granny is a sharp old con woman and leader of her own tribe of gypsies. She is always looking for the next big score.
She raised her grandchildren herself but her parenting methods leave something to be desired. They included selling Groo into indentured servitude. She then fed him a potion which would make him sick, enough for the owners to abandon. That is unless innocent Groo blurted out the entire plan. In this case it was time to flee.