This is based on a recurring nightmare Robert Smith had as a child where he was eaten by a giant spider; Smith says the song is about the fear of sleep.
Lullabies are meant to soothe children to sleep, but some of them have surprisingly catastrophic endings. The most famous lullaby, "Rockabye Baby," ends:
"When the bough breaks, the cradle will fall
And down will come baby, cradle and all"
According to Robert Smith, the lullabies his father sang to him had similarly tragic endings. "There would be something like 'Sleep now, pretty baby,' and then there'd be an 'Or you won't wake up at all' coda to the song," he said.
The 1990 Brit award winning music video was inspired by David Lynch's 1977 debut horror movie Eraserhead.
This song had the Cure's best chart placing in the UK.