'Game of Thrones': These lesser known characters will play a pivotal role in the final season

'Game of Thrones' has one of the largest ensemble casts on television and it introduced us to many characters that we came to know and love — before they were killed off ever so suddenly.

While most of the human characters on the show inspire little faith in humanity because of their propensity for treachery and backstabbing, the show's vast universe would seem incomplete without the giants, humanoids, witches, and, of course, the dragons. It is these characters that make the series truly remarkable and are sure to play a pivotal role in the upcoming final season.

The Children of the Forest:

"In the Dawn Age of Westeros, before the coming of man and the raising of castles and cities, there were only the Children of the Forest." — Bran Stark

The Children of the Forest are a humanoid, magical race who were reportedly the original inhabitants of the continent of Westeros. The Children of the Forest remained mere myths before the humans encountered them again. While they seem to have died out, we know that George R. R. Martin has a habit of bringing pivotal characters, like Jon Snow, back from the dead. After all, they played a big role in their creation of The White Walkers and, after crossing the Ice Wall, the last Children of the Forest may have been wiped out, or so it seems. They are magic, after all, and may seek to aid Bran once again in his Greenseeing journeys, maybe even changing the whole course of this bloody history.

The Giants:

Giants are another legendary non-human race who are in excess of 15-feet tall and have the strength of 12 men. They inhabit the coldest regions of North Westeros and it is even said that Bran the Builder enlisted the aid of giants to raise the Wall.

In the series, we see what's supposedly the last of the Giants, Wun Wun, fall to Ramsay Bolton's blade, but the Giants also existed long before the encroachment of The First Men. There may be a lot more 15-foot-tall men hiding more further up North, and may just be waiting for The King in the North to unite them once again. So we could see them rise in the new season.

The Witches:

The official religion of Westeros is the worship of The Seven: the Father, the Mother, the Maiden, the Warrior, the Smith, the Crone, and the Stranger. However, witches say "screw it" and go on to influence main characters in the series by making accurate prophecies in the series. Maggy the Frog, made the prophecy of the Valonqar (High Valyrian for "little brother") where she says that Cersei will get killed by her little brother who could be either Jaime Lannister or Tyrion Lannister (little because of his dwarfish stature).

There is also a theory that Old Nan is a witch due to her incredibly accurate stories of the past and future, and with Dragonglass and Valerian steel being in short supply, our heroes may enlist the help of the witches for more firepower.

The Deep Ones:

One of the only races to be fleetingly mentioned in the series have yet to make an appearance. The Deep Ones are said to be a race of half-human, half-fish like creatures who were said to inhabit the depths of the seas and torment all the seafaring people. They are essentially Merlings (the inclusive term for both "Mermaids and Mermen"), but they don't resemble 'The Little Mermaid' in any sense, being more grotesque than their usual fairytale counterparts.

With the whole world set to turn to ice by the White Walkers, we may just see the Merlings come out of their murky depths in order to aid the humans but, with their history, we may just see the White Walkers finding a new source of wights (the undead), while simultaneously gaining control of the seas. 

'Game of Thrones' returns with the final season on April 14 and will be available on HBO. You can check out the trailer below.