Gregory (Xander Berkeley), the cowardly leader of the Hilltop colony, is The Walking Dead's slimiest villain. Negan (Jeffrey Dean Morgan) may be more dangerous, but Gregory poses a threat to Maggie (Lauren Cohan) and the other Alexandrians because of his rat-like willingness to do anything to protect himself. Gregory has lasted so long in this post-apocalyptic world by currying favor with the right people and always looking out for No. 1.

He showed his weaselly true colors a few times in Sunday's episode "Something They Need." He went to Maggie, who has been living at Hilltop since Glenn's (Steven Yeun) death and training the somewhat soft agrarian community into a fighting force, and said he'd like to get on the same page with her. Of course, as soon as she turned her back, he considered stabbing her. Just then, a walker appeared, and he was too scared to take care of it, having never killed one before, and let pregnant Maggie handle it for him. Then she saved his life when a second walker got him on the ground. After that, he'd had enough of Maggie, and decided to take Negan's second-in-command Simon (Steven Ogg) up on his offer to come see him at Savior HQ if he needed help taking care of any problem. Gregory has been wanting to snitch on Maggie, who's not supposed to be at Hilltop, for a long time, and now he's going to do it.

Xander Berkeley, <em>The Walking Dead</em>Xander Berkeley, The Walking Dead

Gregory is an over-the-top, mustache-twirling type of bad guy, and Berkeley has fun playing him as such. When he was offered the part, the character description was of an irredeemable "sh--heel," a type Berkeley has played so many times in his lengthy career that he told showrunner Scott Gimple that he wasn't interested unless he could find a way to add something fresh to the character.

"It came out of asking Scott the question, 'What can I bring to your show that you don't have?'" Berkeley tells TVGuide.com. According to Berkeley, Gimple felt the show had gotten a bit turgid and too much like a Southern drama, so they thought, "let's crack the window open and let a nice Northerly breeze come through, but from a guy who is maybe a shuckster, who has learned, like many charlatans do, to adapt to their environment, so you can't really be sure where he's from."

Berkeley thinks Gregory may have run a car dealership, which gave him the ability to sell himself into getting a position of leadership and keep things "managed and running on time." As the actor explains, Gregory thinks of himself as a great man, despite the evidence to the contrary.

What makes Gregory interesting, at least in Berkeley's eyes, is that he has a sense of humor. It's the gallows humor of people in life-threatening situations, and not everyone gets it, but it's there. Berkelely plays him as someone who thinks he's hilarious and charming, which is how he keeps him from becoming utterly unctuous and no fun to watch.

"There's a difference between hating him and being disgusted by him, and hating him and getting a huge kick out of hating him," Berkeley says.

He's often paired in scenes with Simon, who Steven Ogg also plays with a weird sense of humor. They each bring a different, campier energy than the show usually indulges in, and Berkeley says they're encouraged to really go for it.

"At one point, I remember we were playing a scene, and I went to the director and said, 'Are you sure this is what you want?' And he went, 'More. And bigger.' And I said, 'Bigger? I kind of feel like we're erring on the side of big already.' And he went, 'Scott says do not hold them back.'"

Xander Berkeley, Tom Payne, Steven Ogg; <em>The Walking Dead</em>Xander Berkeley, Tom Payne, Steven Ogg; The Walking Dead

Gregory and Simon bounce off each other in such entertaining ways that Berkeley says the show has developed a new camera move to capture each actor's facial expressions. They're each so alive in the moment that they couldn't match Ogg's behavior in one take to Berkeley's in another, because each take was so different — "a weird little organism of interactivity," as Berkeley puts it. They don't improvise words, but they improvise their expressions. So the camera people position themselves to get each actor individually as well as together during a take, which isn't how they normally shoot.

Berkeley would love for The Walking Dead to do a Gregory-Simon bottle (of tequila) episode in Season 8, which he confirms he'll be back for.

"It's fun to imagine where [the writers] may take them next season, when the inevitable get-together happens," Berkeley says.

The Walking Dead airs Sundays at 9/8c on AMC.