"The Big Mom Pirate Crew"
The Big Mom Pirate Crew led by Charlotte Linlin one of the "Yonko" is mostly made up of her biological children. It's a massive pirate organization that does not permit any following from outsiders (i.e. outside allies etc.). and has a total bounty exceeding 10 billion berries and such, boasting overwhelming military might.
The Big Mom Pirates base of operations is "Totland", a nation built in the new world of the Grand Line. One special characteristic of this nation is that it houses people from all kinds of races all over the world.
In pursuit of Strawhat Luffy, she infiltrated Wano Country, has formed an alliance with Kaido and has quickly amounted even more overwhelming military might as a result.