Squirmles, or Magic Twisty Worms, was a toy made out of a soft and fuzzy material in the shape of a worm. One pulled the invisible string and made him crawl over anything. Came out in the early '70's, about '73. Cute lil guy.
The toy came out around 1977, they were fuzzy little snake-like creatures that had fishing line attached to the front, so the idea was that you would wrap the string around you finders, or something similar and pull, creating the illusion that the squirmle was alive and moving about.
A caterpillar attached to a string. You would pull the string around your fingers or arms like the caterpillar was moving
A fuzzy worm that came in all rainbow colors that had a clear string tied to its nose. You would tie the end of the string around a button on your shirt and make it weave in and out your fingers. They come in many colors like orange, purple, or yellow. They work by simply weaving the clear string through your fingers and pulling the worm through, creating an illusion of movement and life. The trick possibilities are endless.
They have many names such as "squirmle", "string worms", or "worm on a string".