'Cäsar' (ii) was a German unrealised naval plan for attacks on Allied shipping in the Kola inlet of the northern USSR (January 1945).

The operation was to have been launched from small ports in the northern part of German-occupied Norway using 'Biber' type midget submarines. With a displacement of 5.6 tons and submerged speed of 5.3 kt on its 13-hp (9.7-kW) electric motor, the one-man 'Biber' was armed with two externally mounted 21-in (533-mm) torpedoes or mines, and was intended for attacks on coastal shipping. The 'Biber' was hastily developed to help meet the threat of an Allied invasion of Europe, and the rushed development process resulted in basic technical flaws that, combined with the inadequate training of their operators, meant the type posed no real threat to Allied shipping, despite the delivery of 324 such midget submarines.

In January 1945 an attempt was made to stage an attack on targets in Vaenga Bay, part of the Kola inlet. Here the Germans hoped either to attack one of the convoys which paused there to refuel and take on ammunition or to attack the Soviet battleship Arkhangyel’sk, which was the British Royal Sovereign on loan to the USSR. Neither the battleship nor a convoy were in the port at the time of the planned attack, for which U-boats were to carry the 'Biber' craft within range of the harbour. U-295, U-318 and U-716 departed Harstad in northern Norway on 5 January with 'Biber' craft carried on their casings. However, the vibration of the U-boats' engines caused the stern glands of the 'Biber' craft to leak, allowing water to reach their machinery spaces, and as a result the mission was abandoned.