Alongside South Park and Family Guy, Pokemon has made it to TIME’s Top Ten Controversial Cartoons and takes up the number seven spot.

While the other cartoons are on the list for offending people, Pokemon gets the seventh spot for giving people seizures in one of its episodes. On December 16, 1997 this certain episode caused some 12,000 people to get symptoms from nausea to seizures and about 700 were sent to the hospital.

The cause of all this? A 5 second flashing of red and blue lights that triggered photosensitive epilepsy in some people. Sounds so innocent, yet so deadly.