borja / herocalf

    return nil unless progenitores.count == 2

    mama = progenitores.last # Allways in the same position

    # Check class type, for polyform.

    case mama

    when Fixnum then return { 'type' => 'pj',  'char' => hero(mama) }

    when String then return { 'type' => 'pnj', 'char' => mama }

    else return "Fallo de madre => #{mama.class}"

    end

  end

  def descendientes

  def padre

    return nil unless progenitores

    papa = progenitores.first # Allways in the same position

    case papa

    when Fixnum then return { 'type' => 'pj',  'char' => hero(papa) }

    when String then return { 'type' => 'pnj', 'char' => papa }

    else return "Fallo de padre => #{papa.class}"

    end

  end

  def madre