The Shrinking of Treehorn is a novel by Florence Parry Heide, illustrated by Edward Gorey, and first published in 1971, totaling 63 pages.
The start of the book introduces readers to the aforementioned Treehorn, a young boy who many people around him think likes to lie or over exaggerate a number of things in his life. Most seriously, Treehorn claims to his family that he is shrinking. But his parents, resigned to the fact that Treehorn is prone to lying, don't believe Treehorn's contention that he is shrinking. Treehorn's mother, for instance, tells him that it's okay if he wants to "pretend" to be shrinking, but he can't pretend to be shrinking "at the table."
But Treehorn's claim is true. He really is shrinking and is becoming more diminutive as each second passes. Still, not everyone in his life believes that he is shrinking despite evidence to the contrary. His teacher tells Treehorn that people don't shrink in their class and sends Treehorn to the principal's office. And his parents consider that "Maybe he's doing it on purpose, just to be different."
Eventually, Treehorn becomes so small that he is unable to function. He spends some time at his miniature size but is eventually returned to his normal size after he engages in a magic game.
