'Mimsy' was a British unrealised concept by Colonel R. Peter Fleming’s 'D' Division deception organisation in Burma, and modelled after 'Llama' (a radio-equipped Libyan left by the Italians to report on events in Tripolitania but 'turned' by the British), to 'blow' a double agent and thereby provide a channel of communication with the Japanese military in South-East Asia (1945).

There was considerable discussion of the plan without Admiral the Lord Louis Mountbatten’s South-East Command and in London, but the Japanese surrendered before any decision on the plan’s implementation could be reached.