Pictures Philadelphia Zoo Announces Return Of Zoo Key, New Exhibit Creatures Of Habitat April 5, 2019 / 3:56 PM EDT / CBS News (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon) Philadelphia Zoo Announces Return Of Zoo Key And New Exhibit Creatures Of Habitat 11 (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon) (Credit: HughE Dillon)