Eeyore in Winnie the Pooh is an example of a cartoon donkey.
A person who makes a very stupid decision like an obvious lie or declining to do homework he knows the teacher will check is an example of a donkey.
An animal symbol used by the Democratic political party is an example of a donkey.
Origin of donkey
- Perhaps from the name Duncan or of imitative origin
From American Heritage Dictionary of the English Language, 5th Edition