The
Person from Porlock was an unwelcome visitor to
Samuel Taylor Coleridge during his composition of the poem
Kubla Khan in 1797. Coleridge claimed to have perceived the entire course of the poem in a dream (possibly an
opium-induced haze), but was interrupted by this visitor from
Porlock while in the process of writing it.
Kubla Khan, only 54 lines long, was never completed. Thus "Person from Porlock", "Man from Porlock", or just "Porlock" are literary allusions to unwanted intruders who disrupt inspired creativity.