Syldavian is a fictional West Germanic language created by Hergé as the national language of Syldavia, a small fictional Balkan kingdom that serves as a major setting in many of "The Adventures of Tintin" stories.
 Hergé modeled the language on Marols, a dialect of Dutch spoken in and around Brussels.
 The entire corpus of the language has been analyzed by Mark Rosenfelder.
The "Word of Thoth" is a fictional language created by Matthew Reilly that has, so far, appeared in "Seven Ancient Wonders" (published in U.S.A. as "Seven Deadly Wonders"), "The Six Sacred Stones", and "The Five Greatest Warriors".
Amarantine was the sixth studio album by Irish singer, songwriter and musician Enya, released on 21 November 2005 by Warner Music internationally and on 22 November 2005 by Reprise Records in the United States.
 Following the release of her compilation box set "Only Time – The Collection" (2002), Enya took a short break before she started work on a new album in September 2003, her first since "A Day Without Rain" (2000).
 "Amarantine" was recorded in Ireland with her longtime recording partners, arranger and producer Nicky Ryan and his wife, lyricist Roma Ryan.
 It marked Enya's first album without a song recorded in Gaelic lyrics, and her first sung in Japanese and Loxian, a fictional language created by Roma.
The Dothraki language is a constructed fictional language in George R. R. Martin's fantasy novel series "A Song of Ice and Fire" and its television adaptation "Game of Thrones", where it is spoken by the Dothraki, nomadic inhabitants of the Dothraki Sea.
 The language was developed for the TV series by the linguist David J. Peterson based on the Dothraki words and phrases in Martin's novels.
The Black Speech is a fictional language created by J. R. R. Tolkien.
Watership Down is a fantasy adventure novel by English author Richard Adams, published by Rex Collings Ltd of London in 1972.
 Set in southern England, the story features a small group of rabbits.
 Although they live in their natural environment, they are anthropomorphised, possessing their own culture, language, proverbs, poetry, and mythology.
 Evoking epic themes, the novel follows the rabbits as they escape the destruction of their warren and seek a place to establish a new home, encountering perils and temptations along the way.
Ku is a fictional language appearing in the 2005 drama/thriller film "The Interpreter".
 In the film, Ku is a language spoken in the fictional African country of Matobo.
 The constructed language was created for the film by Said el-Gheithy, the director of the Centre for African Language Learning in Covent Garden, London.
The word codice_1 (, Klingon for "small gathering") is generally used for any kind of gathering where people may talk about or in Klingon, a fictional language created for "Star Trek".
 In Germany, the word has become commonly used for a specific annual meeting in Saarbrücken, because it is the largest meeting of its kind.
Lapine is a fictional language created by author Richard Adams for his 1972 novel "Watership Down", where it is spoken by rabbit characters.
 The language was again used in Adams' 1996 sequel, "Tales from Watership Down", and has appeared in both the film and television adaptations.
 The fragments of language presented by Adams consist of a few dozen distinct words, and are chiefly used for the naming of rabbits, their mythological characters, and objects in their world.
 The name "Lapine" comes from the French word for rabbit, "lapin", and can also be used to describe rabbit society.
A planned or constructed language (sometimes called a conlang) is a language whose phonology, grammar, and vocabulary have been consciously devised for human or human-like communication, instead of having developed naturally.
 It is also referred to as an artificial or invented language and in some cases a fictional language.
 There are many possible reasons to create a constructed language, such as: to ease human communication (see international auxiliary language and code), to give fiction or an associated constructed setting an added layer of realism, for experimentation in the fields of linguistics, cognitive science, and machine learning, for artistic creation, and for language games.

Question:  Lapine is a fictional language created for a novel published by who?
Answer: Rex Collings Ltd of London