The Blob, Steve McQueens first movie I think. Went to school with the Son of the man who made the movie. One day he brought pieces of the Blob to school. It was like silly putty in a way. Rolled into a ball it would bounce like crazy all over the place. I wish I had kept it but it had no notice of authenticity. Lol
Definitely a cult hit, but I think it was MST3K material.