Peter was a cat who served as Chief Mouser to the Cabinet Office of the United Kingdom between 1929 and 1946.

In 1929, the Treasury agreed to allow one penny daily for Peter's upkeep, which included his food and wellbeing requirements.

It was remarked that when the Home Office was relocated to Bournemouth during World War II, Peter's services were missed so much that they applied for allowances for the upkeep of two cats.

He served under five prime ministers in Conservative, Labour and coalition governments, during a period of British history defined by the Great Slump and World War II.

Peter's tenure defined multiple precedents for the Chief Mouser position, which have been emulated by his successors in the role.