"He died in the night and his wife called me this (Saturday) morning on the phone," Robert Walter, his former adviser and a friend "for 35 years" said, adding that Ungerer died at his daughter's home.
"He was an all-round genius, a man who was talented in everything. He loved literature. He used to say 'I write about what I draw and I draw what I write'," he said. Originally from Alsace in eastern France, Ungerer lived in the United States and Canada before settling in Ireland.
He was obsessed with books from an early age.
Born into a family of watchmakers in 1931 in the Alsatian city of Strasbourg, Ungerer lost his father when he was three-years-old. Ungerer donated more than 11,000 original works of art, sculptures, books and toys to a museum devoted to his work and life, which opened in 2007 in his birthplace Strasbourg. He was awarded the Legion of Honour by France in 1990 and was elevated to Commander of the Legion of Honour in 2018.