There's a crucial aspect to The Walking Dead that really doesn't get as much universal credit as it deserves. The practical effects. Of course there will be times when vast shots of the walker hordes need to be created with Hollywood magic, but for scenes like the one above, the fact that hundreds of REAL people are snatching, grabbing and hissing dramatically lifts the entire show. No machine could ever match a human when it comes to...being human. It sounds obvious, but it's true. Instead of TV-level animations and the characters reacting to nothing, the actors are IN the situation and the extras are unrelenting. Glenn and Nicholas' scene carries real weight, and a huge part of that is down to the realism of it all.