The Complete Guide to All 21 Major Houses on Game of Thrones

Location: The Westerlands
Sigil: Three black dogs on a yellow field
Major members:

• Gregor Clegane, "the Mountain," personal bodyguard to Cersei Lannister
• Sandor Clegane, "the Hound," former bodyguard to King Joffrey and brother to Gregor

Why they matter:
The Mountain currently holds the title of scariest zombie giant in all the Seven Kingdoms.

It looks like the Hound is currently seeking some sort of revenge on the Brotherhood Without Banners, who killed the religious group who saved his life and took him in.

And if what fans are hoping for comes true, the two brothers are headed for the ultimate showdown between the crown and the Faith: Cleganebowl.