Wil (Willibrord Joseph) Huygen (born 1923), is a Dutch book author. He is best known for the picture books on gnomes, illustrated by Rien Poortvliet.

Huygen, a painter in his own right, was born in Amersfoort, Holland. The seventh of ten children, his primary occupation is that of a physician. This helps to explain the method he uses to give realism and a sense of authenticity to his children's books about Gnomes. He still calls Holland home and live there with his wife. His five children are grown.

The first and most well known in this series is Gnomes (published in 1977, and originally known as Leven en werken van de Kabouter in Dutch). In the second book (De oproep der Kabouters) both Huygen and Poortvliet make appearances themselves in both the story and the illustrations as they get contacted by the gnomes because of Gnomes book they have written together.

Rien Poortvliet (August 7, 1932 – September 15, 1995) was a Dutch draughtsman and painter.

Born in Schiedam, he was best known for his drawings of animals and for "Gnomes" in the famous series of books published by Harry N. Abrams, Inc. of New York City.

Being a plasterer's son from Schiedam, making a living as an artist did not seem an option for Rien Poortvliet. His parents were strict Dutch Reformed and were opposed to the idea of their oldest son going to an art academy.

Rien's aptitude for drawing showed early on. After primary education the young Rien worked at an ad agency, where he could make some use of his talent. He unmistakably also had talent for the advertising profession, because after he had completed his draft time in the Navy he rose to senior manager at Lintas, Unilever's ad agency.

Yet Rien took more pleasure in the work he did on the side for several publishers. He illustrated various books, among them works by Jaap ter Haar, Leonard Roggeveen and Godfried Bomans. He was also a passionate hunter, which led him to drawing various nature subjects.

By the end of the 1960s, Poortvliet was able to make a living as an independent illustrator. To supplement his income, he made a book out of his drawings and watercolours based on his hunting experiences. Later on, he also made a similar work concerning the life of Jesus Christ.

Poortvliet saw himself as a characteristic narrator. His drawings told the tale, and at most he added a short caption.

For years his works were published by Van Holkema en Warendorf in Bussum, where his "Leven en werken van de Kabouter" (co-authored by Wil Huygen, English title is "Gnomes") saw an astonishing 59 printings. With the Gnomes series Poortvliet acquired international fame. While he was alive, but more so after his death this series took on a life of its own, and was turned into an animated series.

His books were translated into English, French, German, Swedish, Finnish, Italian and other languages