Scout calls Dill a “pocket Merlin.” This is an allusion to what legend?
The legend in question is that of King Arthur and the Knights of the Round Table. One of the most memorable characters in that epic tale is Merlin the wizard.
It is summertime in Maycomb and that means playtime for the kids, with lots of opportunities for getting into all kinds of scrapes and crazy adventures. Scout and Jem are pretty imaginative when it comes to thinking up new ways to occupy themselves during those long, hot summer months, but Dill is in a different class all of his own:
Thus we came to know Dill as a pocket Merlin, whose head teemed with eccentric plans, strange longings and quaint fancies.
So says Scout. The boy clearly has a rich, imaginative fantasy world, the kind of thing that most children would find themselves being drawn to immediately. Scout's reference to "pocket Merlin" also highlights Dill's somewhat diminutive stature. He is one year older than Scout, yet she still towers over him. But what little Dill lacks in height, he more than makes up for in personality and imagination.