'Kuckucksei' was a German unrealised plan for an offensive against the British forces of Lieutenant General K. A. N. Anderson’s Allied 1^st Army in the Fondouk Pass area of the Dorsale Orientale in eastern Tunisia some 40 miles (65 km) to the north of the Faid pass (February 1943).

The operation was cancelled in favour of 'Frühlingswind' and 'Morgenluft' (i).