That's exactly what we thought when we saw this large species of sand wasp dragging what looked like a large blade of grass (now can see it's a caterpillar of some description).
My daughter has to take the credit as she actually took this shot (using macro mode), but we were so impressed (maybe worried is a better word) that I decided to put it up anyway! As she took it everyone walking past stopped to see what it was we were doing and starred aghast at the size of this thing!!!
According to the book, this species of sand wasp hunts for large caterpillars to stock its nest with! And it does it by paralysing them... euh what a way to go. :(