Dick Bruna, the creator of Nijntje the rabbit, has died at the age of 89.

Creator of who? Yes, Nijntje is the original Dutch name of the beloved bunny Miffy. Also, she isn't Japanese, and she's not friends with Hello Kitty.

So what else do we not know about Miffy the rabbit and her creator?

1. She's more than 60 years old

Mr Bruna created Miffy in 1955 to entertain his then one-year-old son.

He was inspired by a rabbit seen hopping around the garden during a family seaside holiday.

The line of books about the innocent little rabbit has since become a worldwide sensation.

Over 85 million Miffy books have been sold around the world, translated into more than 50 languages.

2. Miffy and Nijntje

But she wasn't known as Miffy then. Her Dutch name comes from "konijntje", which means "little rabbit".

While this makes sense for people in the Netherlands, it's hard to pronounce for many people around the world.

The first English translator for the books, Olive Jones, christened her Miffy.

"The name doesn't have any special meaning, but it is easy to pronounce in all languages," according to the Miffy website.

3. How Miffy became a girl

At first, she was just a character in bedtime stories for Bruna's oldest son Sierk.

But then Bruna drew her on paper, and decided she should be a girl, as drawing dresses was more fun than trousers.

In an interview with the Guardian, Bruna said he only decided she was a girl in the sixth Miffy book - "Miffy's Birthday" (1970).

In that book, she dons a dress with flowers on it.

4. Miffy's hard to draw

Bruna hand drew each Miffy book using a paintbrush, and he said in a few interviews that there are hundreds of versions for each Miffy book.

Minute adjustments are made to give her expressions. Bruna spent much time on her mouth to make it either a little sad or a little happier.

His wife of 64 years, Irene, is the first editor of every Miffy book. She decides which version of the bunny is good enough to go out to the world.

5. Minimalist Miffy

Bruna's style is often described as minimalist. He was inspired by artists including Matisse, Leger and Braque.

"I put away things that are unnecessary, so there is room for the imagination," he once told The Financial Times.

Bruna himself was known for a spartan lifestyle. While the Miffy global empire is estimated to be worth around US$300 million annually, he cycled to his studio in Utrecht every day.

6. Miffy miffed at Hello Kitty

Bruna proclaimed more than once that he thought Hello Kitty is a copy of Miffy. Hello Kitty debuted in 1974.

Both are drawn with simple lines, have oversized heads, and a child-like gaze.

There are differences besides their species - Miffy has a cross for a mouth while Hello Kitty has no mouth; Hello Kitty has a bow in her ear, plus the rabbit is associated with primary colours, and Hello Kitty with pink.

Pink is "not a proper colour", Bruna once told The Guardian.

But the Japanese, champion purveyors of kawaii (cute), are also some of the most ardent Miffy fans.

7. A Miffy copy?

Bruna even brought a copyright lawsuit against Cathy the bunny, a friend of Hello Kitty, in 2010.

An Amsterdam court ordered Sanrio to halt production and sales of Cathy merchandise in the Netherlands, Belgium and Luxembourg. Sanrio appealed the decision.

Both ceased legal action in 2011 after the March 11 earthquake and tsunami. Sanrio agreed to discontinue Cathy, and both sides agreed to donate the legal fees to victims of the earthquake.

Sources: AFP, BBC, The Guardian, The Financial Times, Miffy.com