Pneumatic Elephant
From TowersStreet Wiki
The pneumatic elephant is an animatronic created by John Wardley that sometimes lifts its trunk a bit and squirts water on riders at the end of Dragon Falls at Chessington World of Adventures. It is said in English folklore that if one witnesses the animatronic in full operation then they have been chosen by God, as it is such a rarity.
So we installed a pneumatic elephant at the end, which waves its trunk and literally squirts you as you come into the station. And guests LOVE THAT! - John Wardley, Season Pass Podcast interview