Piglet calls the acorns he likes “haycorns” in the Winnie-the-Pooh stories.
The word is one of the series’ characteristic childlike inventions. Piglet is a small domestic pig who often speaks in a nervous but imaginative way, and his vocabulary helps distinguish him from the other residents of the Forest.
Acorns are associated especially with Piglet’s habits and personality. Although he is often timid, he is also loyal and capable of surprising bravery when his friends need help.
The spelling can be confused with ordinary words such as “hay” or “acorn,” but “haycorns” is the established Pooh expression. It belongs to the language of the original stories rather than being the name of a separate fictional plant.