I don’t know whether this is the Next Big Thing, but my kids love these little things. They come in animal shapes, vehicles, pastries, etc.
They are made of eraser rubber (but don’t actually fit on a pencil) and are each composed of multiple pieces, so each creature is a small, simple 3D puzzle.
The creatures are very cute and something about the colors and the texture of the eraser rubber makes them seem almost like cartoons somehow made real.
They make good party favors or the sort of thing you might include with valentine cards for classmates, or as part of a grab bag.
You can get a big set from Amazon or a pack of 8 or so from some dollar stores. There are some Japanese “$1.50” stores in California that carry them, too.