German torpedo boat Jaguar

Together with the torpedo boat Falke, Jaguar impounded six ships in the Skaggerak during an anti-contraband patrol in 14–16 December.[9] She began a refit later that month at Wesermünde that lasted until March 1940.[10] During the Norwegian Campaign, Jaguar and Falke, among other ships, briefly rendered assistance to the torpedoed heavy cruiser Lützow before continuing onwards to Kristiansand on 11 April with reinforcements.[11] On 4–5 June Falke and Jaguar provided the anti-submarine screen from Kiel, Germany, to the Skaggerak for an unsuccessful attempt to intercept the Allied convoys evacuating Northern Norway by the battleships Gneisenau and Scharnhorst and the heavy cruiser Admiral Hipper. From 21–23 June, Jaguar was one of the escorts for the badly damaged Scharnhorst from Norway to Kiel. Now assigned to the 5th Torpedo Boat Flotilla, Jaguar, and the torpedo boats Kondor, Falke, T2, T7 and T8 escorted minelayers as they laid a minefield in the southwestern North Sea on 7–8 August. The flotilla escorted other minelaying missions in the same area on 14–15 August, 31 August – 2 September and 6–7 September. Reinforced by her sister Wolf, the flotilla made an unsuccessful sortie off the Isle of Wight on 8–9 October. Jaguar and her sister Iltis laid a minefield off Dover on 29–30 October and then again on 2–3 December.[12]

Jaguar and Iltis laid a minefield off Eastbourne on 25–26 February and then again on 5–6 March. The pair escorted Scharnhorst and Gneisenau into Brest, France on 22 March after their North Atlantic raid. Jaguar began a refit the following month in Rotterdam, Netherlands, that lasted until May. She was transferred afterwards to the Skagerrak where she was on convoy escort duties until October. The ship rejoined the 5th Flotilla in France by February 1942. The flotilla joined the escort force for Scharnhorst, Gneisenau and the heavy cruiser Prinz Eugen on 12 February off Cap Gris-Nez during the Channel Dash. From 12 March to 2 April, the flotilla escorted the commerce raider Michel through the Channel despite heavy British attacks, damaging the British destroyers HMS Walpole and Fernie. In September and October, Jaguar was one of the escorts for German blockade runners sailing from ports in the Bay of Biscay en route to Japan.[13]

On 11 March 1943, Jaguar and the torpedo boat Greif were among the escorts for the battleships Tirpitz and Scharnhorst as they moved from Trondheim, Norway, to Bogen Bay, and continued onward to Altafjord with Lützow and the light cruiser Nürnberg from 22 to 24 March. Jaguar, Greif, and the destroyer Z4 Richard Beitzen screened Nürnberg from Harstad to Trondheim and then to Kiel between 27 April and 3 May. On 3–7 May, Jaguar, Greif, the torpedo boat Möwe escorted minelayers in the North Sea as they laid new minefields. In June the boats returned to the Bay of Biscay to help escort U-boats through the Bay and continued to do so into early August.[14]

The 4th and 5th Torpedo Boat Flotillas, consisting Jaguar, Möwe, Greif, Kondor, and the torpedo boats T27 and T29 laid minefields off Le Havre and Fécamp, France, on 21 and 22 March 1944. The flotilla was ordered to transfer from Cherbourg to Le Havre and departed on the night of 23/24 May. Jaguar, Greif, Falke, Kondor and Möwe were attacked by Allied aircraft early the next day and Greif was struck by two bombs and later sank. As the Allies began landing in Normandy on 6 June, the 5th Flotilla, now consisting of Jaguar, Falke, Möwe and T28, sortied multiple times from Le Havre over the next week in attempts to sink Allied shipping. Despite the expenditure of over 50 torpedoes and large quantities of ammunition, they were generally unsuccessful, only sinking the destroyer HNoMS Svenner on 6 June. During an air raid by heavy bombers of RAF Bomber Command on the night of 14/15 June against the harbour and the German warships there, Jaguar and Falke were sunk by bombs.[15]