Doctors Chris and Xand van Tulleken bring you the top animal experts on the planet to show you things that will truly blow your mind! In this episode they find out all about big reptiles. Animal expert Steve Leonard meets Martha the alligator, who has eaten something unusual that is seriously blocking her guts. Clare Balding heads to London Zoo to meet Priscilla the tortoise, who needs an operation on her liver, but vets find operating on a tortoise with a super-hard shell, isn't easy. Show less