Scientific Parasites

Scientific Parasites are a group of creatures in the Land of Ooo who feed on intelligent brain waves. This is why they are commonly found in the pockets of doctors and scientists. These parasites come in many forms and colors and sometimes have the appearance of certain animals. Dr. Donut doesn't have a Scientific Parasite on him, most likely due to his lack of pockets, neither does the Science Cat, despite the pockets on his professorial garb.

Scientific Parasites apparently existed prior to the Mushroom War, because Simon Petrikov (the Ice King) is shown with one in his jacket pocket. When Finn is acting like a doctor he has two science parasites inside his coat pocket. This implies either that Finn is smarter than he appears to be or that the Scientific Parasites are not able to determine who gives off intelligent brain waves and simply assume doctors are smart, or Finn had purposely placed them there, which is unlikely. But for an unknown reason there is also one in Jake's tool belt in "Slow Love."

Gallery
The following gallery shows characters seen with scientific parasites.