Eeyore refers to a fictional character from the book series and cartoon Winnie the Pooh. He is a pessimistic, gloomy old donkey who happens to be a friend of Winnie the Pooh. He is hardly ever happy and when he is he's still sardonic and a bit cynical. His grumpiness might be atrributed to the fact that his tail is affixed to his behind using a pushpin.
In merchandise by the Walt Disney Company, Eeyore always has an uncharacteristic smile.
Eeyore spells his name "eoR".