A question for gen x.

When I was a kid in the seventies and early eighties there was this black tablet that when you lit it on fire expanded into an ash snake.

Does anyone remember what they were called.

UPDATE Thanks to those who responded. Magic snakes or black snakes seems right. I’m thrilled I wasn’t going through a Mandela Affect 😝

Sometimes I drive or walk around the city and can still smell those snakes. Major sensory memory going on