Question: Which "The Chronicles of Narnia" character is prominently featured in "The Lion, the Witch and the Wardrobe" and is a close friend with Lucy Pevensie whom she meets in the Lantern Waste.

Context:
Lucy Pevensie
Lucy Pevensie is a fictional character in C. S. Lewis's "The Chronicles of Narnia" series.
 She is the youngest of the four Pevensie children, and the first to find the Wardrobe entrance to Narnia in "The Lion, the Witch and the Wardrobe".
 Of all the Pevensie children, Lucy is the closest to Aslan.
 Also, of all the humans who have visited Narnia, Lucy is perhaps the one that believes in Narnia the most.
 She is ultimately crowned Queen Lucy the Valiant, co-ruler of Narnia along with her two brothers and her sister.
 Lucy is the central character of the four siblings in the novels.
 Lucy is a principal character in three of the seven books ("The Lion, the Witch and the Wardrobe", "Prince Caspian", and "The Voyage of the Dawn Treader"), and a minor character in two others ("The Horse and His Boy" and "The Last Battle").
White Witch
Jadis is the main antagonist of "The Magician's Nephew" and of "The Lion, the Witch and the Wardrobe" in C. S. Lewis's series, "The Chronicles of Narnia".
 She is commonly referred to as the White Witch in "The Lion, the Witch and the Wardrobe", as she is the Witch who froze Narnia in the Hundred Years Winter.
Susan Pevensie
Susan Pevensie is a fictional character in C. S. Lewis's "The Chronicles of Narnia" series.
 Susan is the elder sister and the second eldest Pevensie child.
 She appears in three of the seven books—as a child in "The Lion, the Witch and the Wardrobe" and "Prince Caspian", and as an adult in "The Horse and His Boy".
 She is also mentioned in "The Voyage of the Dawn Treader" and "The Last Battle".
 During her reign at the Narnian capital of Cair Paravel, she is known as Queen Susan the Gentle or Queen Susan of the Horn.
 She was the only Pevensie that survived the train wreck (because she was not on the train or at the station) on Earth which sent the others to Narnia after "The Last Battle".
Sophie Wilcox
Sophie Elizabeth Wilcox (born 2 January 1975 in Croydon, London) is an English actress who is most notable for appearing in the BBC miniseries adaptation of "The Chronicles of Narnia" as Lucy Pevensie when she was 13 years old.
 She appeared in "The Lion, the Witch and the Wardrobe" in 1988, as well as its sequel "Prince Caspian and the Voyage of the Dawn Treader" in 1989.
Edmund Pevensie
Edmund "Ed" Pevensie is a fictional character in C. S. Lewis's "The Chronicles of Narnia" series.
 He is a principal character in three of the seven books ("The Lion, the Witch and the Wardrobe", "Prince Caspian", and "The Voyage of the Dawn Treader"), and a lesser character in two others ("The Horse and His Boy" and "The Last Battle").
Lantern Waste
Lantern Waste is a fictional place in "The Chronicles of Narnia" series by C. S. Lewis.
 It is a wood and is notable as the place where Lucy Pevensie and Mr. Tumnus meet, which is the first scene of Narnia described in the books.
 The lamppost in the wood is an iconic image of Narnia, and the question of its origin is what convinced Lewis to write more than one book on Narnia.
 One of King Edmund's titles is "Duke of Lantern Waste".
The Chronicles of Narnia (TV serial)
The Chronicles of Narnia is a BBC-produced television serial that was aired from 13 November 1988 to 23 December 1990 and is based on four books of C. S. Lewis's "The Chronicles of Narnia" series.
 The first series aired was "The Lion, the Witch and the Wardrobe" in 1988, the second series aired was "Prince Caspian" and "The Voyage of the Dawn Treader" in 1989 and the third series aired was "The Silver Chair" in 1990.
 This television serial was produced by Paul Stone and teleplayed by Alan Seymour.
 "The Lion, the Witch, and the Wardrobe" was directed by Marilyn Fox, while "Prince Caspian, The Voyage of the Dawn Treader" and "The Silver Chair" were directed by Alex Kirby.
Mr. Tumnus
Tumnus is a fictional character in C. S. Lewis' series "The Chronicles of Narnia".
 He is featured prominently in "The Lion, the Witch and the Wardrobe" and also appears in "The Horse and His Boy" and "The Last Battle".
 He is close friends with Lucy Pevensie and is the first creature she meets in Narnia, as well as the first Narnian to be introduced in the series.
 Lewis said that the first Narnia story, "The Lion, the Witch and the Wardrobe", all came to him from a single picture he had in his head of a faun carrying an umbrella and parcels through a snowy wood.
 In that way, Tumnus was the initial inspiration for the entire Narnia series.
Lucy Barfield
Lucy Barfield (2 November 1935 – 3 May 2003) was the godchild of C.S. Lewis.
 "The Lion the Witch and the Wardrobe" is dedicated to Lucy, who also lent her name to the book's heroine, Lucy Pevensie.
Hundred-Year Winter
The Hundred-Year Winter is a time period in the fictional Narnia universe created by C.S. Lewis.
 It takes place from 900–1000 Narnia time.
 The White Witch Jadis cast a spell to make it Winter all year round, but never reaches Christmas.
 But throughout the story, Aslan is entering Narnia and his presence weakens The White Witch, Jadis, causing Spring and Father Christmas to slowly appear.
 Aslan also brings Peter, Lucy, Susan, and Edmund to Narnia to fulfill the Prophecy of The Four Thrones ("When two daughters of Eve and two sons of Adam sit together in throne at the Cair Paravel, the reign of the White Witch will be over and done.)
 This would put an end to White Witch's plan and her reign and the endless winter would come to an end.
 (The final days of the Hundred Year Winter occur during "The Lion, the Witch, and the Wardrobe".)

Answer: Mr. Tumnus