If you got the Kombat Pack for Mortal Kombat X, you already have the final character Tremor, while everyone else will be able to download him next week.
But as it turns out Tremor might not be the last character after all. Developer Netherrealm Studios hosted a livestream yesterday where they showed Tremor, but also discussed the future of the game. And as it turns out, Tremor is only the "end of Kombat Pack 1″.
That does indeed make it sound like there might be a second (and possibly even more beyond that) Kombat Pack planned, and hopefully, we'll get to know more about that in the not too distant future.