Here is my attempt at a warp rift. It was inspired by this 2d example:

I liked the idea of a warp rift being just a cluster of pitch black tears in space, so I tried to model it in 3d. I carved up a piece of foam, put some outlying foam pieces on cocktail sticks and put some cotton wool in between (all painted black beforehand).

Not sure if I'm completely satisfied with the outcome, but it was fun to build.
Here are some more action shots:

