December 16, 1997 was an animator's worst nightmare: the day a cartoon turned toxic.

[ ... ] So when things went wrong, they went wrong in a big way. The episode broadcast December 16, 1997 included, among other scenes, someone throwing a bomb at Pikachu. Pikachu responds with his ability to shoot out lightning bolts. Both had happened often enough on television with no ill effects. However, this time the combination of the two was at just the wrong rate of strobing. It induced an epileptic seizure in about seven hundred Japanese children. Most recovered quickly, but a few had to be hospitalized overnight.