For a long time, a safe haven for the survivors was symbolised by Dale's RV; as long as you could see it, you were safe. All that was turned upside down in season two however, when the group were caught in the midst of a walker herd, with this cheeky chap in particular making his way onto the vehicle. Dale managed to escape to the vehicle's roof, but Andrea - unaware of the herd until it was already surrounding the RV - had to seek refuge in the bathroom just as the walker arrives. It's an incredibly tense scene, with Andrea barely escaping, having to stab through the walker's head with a screwdriver Dale pushes through the screen roof panel.
24. Drugstore Walker
The drugstore walker is one we encounter at a time where the group start to think they're getting good at dealing with the undead, and provides a darkly comedic wake-up call for them. As Glenn and Maggie search a pharmacy for supplies, they are attacked by this guy, who very nearly bites the latter, only to be struck by a shelf from the former. Just as they think they've escaped, the pair have to try a second time as the walker stands back up, complete with head flopping to one side still barely attached to the rest of its body.