as in the old Bob Newhart Show the actor would be pulling a Larry by: 'hi my name is Larry, and this is my brother Darryl and Darryl.' and 5 minutes later in the same episode 'hi my name is Larry, and this is my brother Darryl and Darryl.
Someone or something that bites your ankles.
To a postman, an ankle biter is often known as a dog.
To an adult, an ankle biter may be a toddler.
To hikers, an ankle biter is sometimes a tick.
And so on.