'Game of Thrones' at Comic-Con 2012: Diana Rigg and many more in Season 3 castAdd to Favorites | Game of Thrones
"I'm going to have to start killing off some of these characters to make room for the new ones," author George R.R. Martin joked at the panel.
Dame Diana Rigg in one of the series' most colorful roles, Lady Olenna Tyrell, known as "The Queen of Thorns" for her acid tongue and sharp wit. (Game on, Maggie Smith! If anyone could take down "Downton Abbey's" Dowager Countess, it's Lady Tyrell.)
Pics: Who's who in 'Game of Thrones'
Another familiar face joining Rigg (best known for her starring role in the 1960s spy-fi series "The Avengers") is Mackenzie Crook as wilding raider Orell. Crook played Gareth in the original version of "The Office" -- his character was the analog to Dwight (Rainn Wilson) -- but is most recognized for his work on "The Pirates of the Caribbean" films.
Here's the rundown of the new cast and the characters they'll play in "Thrones'" third season, premiering March 31, 2013.
Diana Rigg as Lady Olenna Tyrell. Also known as "The Queen of Thorns," Lady Olenna is the grandmother of Margaery and Loras Tyrell and is, in many ways, the true leader of their powerful family.
Mackenzie Crook as Orell. A wildling raider, Orell is a "warg" or "skinchanger," with the ability to enter the mind of an animal and control its actions.
Clive Russell as Bryndon "The Blackfish" Tully. Known far and wide as "The Blackfish," Brynden is a famous knight and the uncle of Catelyn Stark. He quarreled bitterly with his brother, Lord Hoster Tully, and the two were estranged for many years.
Nathalie Emannuel as Missandei. Originally from the peaceful island of Naath, Missandei was sold into slavery as a child, along with her brother. She received education in various languages and became a translator to the slave trader Kraznys in Astapor.
Kerry Ingram as Shireen Baratheon, the only child of Stannis Baratheon. An avid reader, she escapes her lonely life through myths and stories - her books are her most treasured possessions.
Paul Kaye as Thoros of Myr. A key member of the outlaw band known as the Brotherhood Without Banners, he is a Red Priest, in service of the Lord of Light, and originally hails from the Free City of Myr, in Essos.
Thomas Brodie-Sangster as Jojen Reed, a mysterious and enigmatic young man who becomes an important ally to Bran Stark.
Ellie Kendrick as Meera Reed. The eldest daughter of Howland Reed and a staunch Stark loyalist, Meera and her younger brother Jojen seek out Bran Stark to protect him on his hard journey north.
Richard Dormer as Beric Dondarrion. Once the lord of Blackhaven and a celebrated warrior, Lord Beric has now become the leader of the Brotherhood Without Banners, a band of vigilante outlaws. (Dormer is no relation to Natalie Dormer, who played Margaery Tyrell in Season 2 of "GoT.")
Kristofer Hivju as Tormund Giantsbane. A famed wildling warrior and chief lieutenant of the "King Beyond the Wall," Mance Rayder, Tormund is fearsome and strong, with a large build and a beard to match.
Philip McGinley as Anguy, an extremely skilled archer and key member of the outlaw band known as the Brotherhood Without Banners.
Tara Fitzgerald as Selyse Baratheon. The wife of Stannis Baratheon, Selyse spends much of her life in seclusion, shut away in a gloomy tower.
Tobias Menzies as Edmure Tully. The younger brother of Catelyn Stark, Edmure has recently become Lord of Riverrun in the wake of his father's death.
Anton Lesser as Qyburn, a former maester of the Citadel, who was stripped of his chain many years ago.
Watch the actors introduce themselves here: