The skin of a Poliwag is semi-transparent, especially in the white circle on its chest. Through detailed study, its internal organs are visible – not just the spiral-shaped intestine, but if you look closely, even the brain and heart can be seen. This fact has made Poliwag a staple of science classes for young children, as they could be used to study anatomy without forcing the children to dissect a pokemon.

In ancient times, it was from analyzing Poliwag that the science of medicine begun. Observing them in nature allowed people around the world to discern the functions of various body parts, along with the common mishaps they suffered. It was not perfect knowledge – Poliwag are amphibians, only distantly related to humans – but knowledge in this field grew by leaps and bounds, and in the age of antiquity man through Poliwag had already begun to understand that humans and pokemon are related.

Interestingly, it was only a few centuries ago that Chansey were effectively domesticated, and before this, it was Poliwag which nurses kept on hand in pokemon centers. As assistants, they were not nearly as helpful as Chansey. Their oily skin, hypnosis technique and water type made them worth having around, but their use owed as much to tradition as to utility.