The meaning of "Lullaby" has been speculated by fans, including as a metaphor for addiction or for depression, and Smith has offered multiple, different explanations as to its theme or content. Tim Pope, a long-time collaborator of The Cure on many of its music videos, reported that "Lullaby" was, in fact, an allegory for lead singer Robert Smith's druggy past.
The music video for "Lullaby" was filmed at a sound stage in London, England. It features Robert in bed, in a dream sequence, and the rest of the band playing tin soldiers who sporadically appear throughout the music video for a few seconds. The music video, during which Smith plays both the cannibalistic "spiderman" mentioned in the lyrics (which does not refer to the similarly-named Marvel Comics superhero) and his intended victim, concludes with Smith being swallowed by what appears to be a giant spider.