"Rage of Caliban" is the sixth episode of Constantine. It aired on November 28, 2014.
Synopsis
When a young boy is taken over by a malevolent spirit, John must put aside his misgivings over exorcising a child and convince the parents that their boy is not all that he seems.[src]
The best known literary Caliban appears in Shakespeare's "The Tempest" and is the misshapen son of a witch, with magical powers of his own. The codename has, however, been used in comics on several occasions.
A trick-or-treater can be seen dressed as Robin, another famous DC character, famously known for being the sidekick of Batman.