Hunters were probably the only real 'oh shi-' moment I had in all of Half Life... that and the ending of Episode 2.
I was feeling pretty sick while I played Ep2 because I get serious motion sickness from source engine games(Aside from TF2) like many people; but I still decided to play Ep2 from beginning to end in one sitting on a crappy Saturday. I did the same thing with Portal... curse you weekends with bad weather!!
Perfect timing, I just played through Episode 2 again just recently.. god I love these enemies, they have such cool attacks, sounds, and looks.. I only wish we could have fought more of them. Though it looks like they've been deployed to the arctic location in Episode 3..so yay!
That's actually not a bad idea, I had some other background elements and some colored motion blur but took them out because they it was busying up the composition. A scanner would totally fit since they're small and just fly around. Thanks!