The greasers are a minor gang formed by Greasy Johnny, preying on the poorest of the poor who have taken shelter in the northern sewers. The greasers shake the people living down there for caps and everything else of value, barely making 50 caps per week. However, to Greasy, that's more than enough to warrant preying on the people of the sewers.  Most of his gangers have whatever salvaged weapons they could get their hands on, such as pool cues or baseball bats, with the luckiest having a varmint rifle. Greasy is the luckiest one, toting an energy weapon... Much like the Fiends that plague other sections of the sewers.
↑The Courier: "Got any more work for me?" Crandon: "Good work with those newcomers. I think you can handle more serious business... with more serious rewards. There's a handful of greasers down in the sewers causing trouble. They ain't packing too much iron, but I'd like them dealt with all the same." The Courier: "What kind of trouble?" Crandon: "Folks that don't belong. Murderers, rapists, extortionists, and everything in between. You know, business as usual in North Vegas, stranger." (Crandon's dialogue)