On Thanksgiving 2008, cartoon network had a float in the Macy's Day Parade. They began with a normal song and suddenly, the all too familiar song started and Rick Astley Rick Roll'd the entire country.
Someone or something that bites your ankles.
To a postman, an ankle biter is often known as a dog.
To an adult, an ankle bitermay be a toddler.
To hikers, an ankle biter is sometimes a tick.
And so on.