The crew of the U-601 killed a polar bear; 1943. 
The German submarine U-601 took part in ten patrols, exclusively in the Arctic Ocean.
In November 1942, along with U-625 as part of wolfpack Boreas, attacked Convoy QP 15 and sank the Soviet cargo ship Kuznets Lesov.
She was sunk by depth charges in the Arctic Ocean on 25 February 1944 NW of Narvik, Norway by a RAF Catalina. All 51 hands were lost.

Wildlife killers

...from a very low flying aircraft.
German submarine U-848 was  a long-range Type IX, with four bow and two stern torpedo tubes. 
  On 2 November 1943, she torpedoed and sank the unescorted British steamship Baron Semple, a freighter, NW of Ascension Island, in the South Atlantic. All hands were lost.
  She was intercepted on 5 November 1943, off the coast of Brazil, by the United States Navy aircraft PB4Y Privateer from Patrol Bombing Squadron VB-107. She was depth charged and sunk.



U-848 under attack...

German submarine U-2326, under command of  Oberleutnant zur See Karl Jobst, was a Type XXIII U-boat of Nazi Germany's Kriegsmarine during World War II. Here he is on the right, surrounded by British naval officers, after surrendering the U-boat to the British Navy at Dundee, Scotland; 14 May, 1945.