A glimpse of the parts beforehand. That’s nasty.
Here is the finished product after inserting the (computer) mouse into the (real) mouse. Oh yum.
And here it is being used by someone’s hand. Who knows who that is. All I know is that I don’t want that to be my hand. And I don’t want to shake their hand either.
So there have some of the interesting pictures that I saw over at Instructables. That is disgusting, but I think that is still fairly cool. Why is that cool? Well just imagine how much more disgusted everyone else would be if they saw you use it. I could see how this could be the source of many many practical jokes. Find it gross, find it humorous, or find it useful. Whatever the case, it has to evoke some feelings in you.