Meet the Lobster Moth

I came across a picture of this unusual moth caterpillar called the Lobster Moth or Lobster Prominent (Stauropis fagi).  I've never seen anything like it.  Its front legs are huge and it really looks like some alien creature.  The adult moth is a nondescript Notodontid found throughout the Palearctic that looks like many species I find outside my house.  Some of the local species have pretty unusual looking caterpillars with weird humps and tentacles, but nothing like this species.