Although my parents usually let my siblings and I watch our animated programming unsupervised, there were certain programs which my mother never quite approved of. One which she frequently took issue with was the Smurfs due to the emphasis on sorcery on that program. Of course, magic aside, the Smurfs were fairly inoffensive, weren't they? Weren't they???
There is one episode which - as the internet has taught me - made an impression on the young minds watching it. It's called "The Purple Smurfs" and involves a disease running through the Smurfs which turns their skin dark purple; they become violent and spread said disease by biting others; soon, the villagers are outnumbered and under siege by hordes of the infected and all their plans seem doomed to failure with defeat inevitable... yes, for many of us, "The Purple Smurfs" were our introduction to tropes found in zombie fiction!
The story itself came from the original French comics, only there it was called "the Black Smurf." Perhaps there were race-based concerns about "black Smurfs" in the USA? It does sound like the blaxploitation version of the Smurfs (who's the Smurf who won't smurf out when smurfing's all about? BLACK SMURF!).
My mother wanted to protect me from harmful ideas, but "The Purple Smurfs" was a first season episode and thus among the first I saw; damage done. Still, even in a pseudo-zombie story, the Smurfs are inherently innocuous; this was an effectively frightening program when I was a tot, but it also helped prepare me for worse sights to come.