After adding the communities located at the Sanctuary, the Hilltop, the Kingdom, and Oceanside, The Walking Dead has a new gang that prefers to call the junkyard their home. They've been confirmed to be the Scavengers, but the Scavengers in The Walking Dead comics are notably different from this junkyard crew. Viewers know the group's name because actress Pollyanna McIntosh stated at the very beginning of the Talking Dead episode following "New Best Friends" that her character, Jadis, is in fact the leader of the Scavengers. Yet, the Scavengers coming to the AMC show in Season 7 really hadn't been on fans' radars and if you look at the Scavengers in the comics, that's for a very good reason.
For comic readers and non-comic readers alike who thought that the new group introduced in the Season 7 midseason premiere was brand new to The Walking Dead world, the AMC series pulled one over on you (and me) since the Scavengers do appear in the Robert Kirkman comics. However, the Scavengers were not nearly as important in the comics as it seems that they will be on the TV show. From what has been shown so far, the TV series has taken serious liberties with the comic creation and though their TV counterparts share some basic similarities (i.e., scavenging), that's about as far as the comparisons go.
While it's not really a new phenomenon for the show to change up what happens in the comics, by reading up on the Scavengers you'll see this is a pretty big divergence. First off, although the Scavengers in The Walking Dead comics appeared when Rick and co. were at Alexandria like they did on the TV series, they were introduced before the Saviors. To understand the timeline, the Scavengers were actually accidentally led to Alexandria by Glenn and Heath and were drawn even closer when Rick shot Pete (Jessie's husband), which occurred all the way back in the Season 5 finale on the TV show.
The TV Scavengers have created their own way of speaking and dressing (kind of like King Ezekiel, but way less endearing) and all have funky and presumably made-up names like Jadis, Tamiel, and Brion. In the comics, the only named Scavenger was their leader — with the much more common name of Derek — and while there might be at least 100 Scavengers on the TV show, their numbers were significantly smaller in the comics.
In the comics, the Scavengers were also very clearly villains and I'm not quite sure what to make of the TV Scavengers just yet. But while the Scavengers were bad guys in the comics, they didn't last very long since when they attacked Alexandria, a still-living Andrea killed their leader. The rest of the Scavengers were also killed quickly by the people of Alexandria, so they really weren't a major problem for Rick. The biggest issue they caused was that this skirmish drew walkers to Alexandria, which resulted in the deaths of Jessie and Ron later. In the way they attacked Alexandria, how quickly they were disposed of, and the walker infiltration that ensued, the Scavengers from the comics can be most easily compared to the Wolves, which were a group created for the TV series.
If you're looking for answers to what the hell is up with these strange Scavengers on The Walking Dead, I'm sorry to say that the comics won't provide many answers for you. The junkyard is some new territory and these TV Scavengers with their weaponized walkers could turn out to be a useful asset or just another problem for Rick to fix. But one thing I can say for them is at least they're more civilized than their comic counterparts — even if I have no idea what their civilization is all about.