![6+girls akiyama_yukari arms_up blank_eyes boots bow braid brown_footwear brown_jacket camouflage cannon caterpillar_tracks chi-hatan_(emblem) chi-hatan_military_uniform copyright_name emblem fukuda_(girls_und_panzer) girls_und_panzer ground_vehicle guard_rail hair_ribbon hand_on_hip happy hase_yu holding hosomi_(girls_und_panzer) ikeda_(girls_und_panzer) jacket knee_boots kneeling landship long_hair long_sleeves military military_uniform military_vehicle miniskirt motor_vehicle multiple_girls nishi_kinuyo o-i_superheavy_tank_series phone_booth pleated_skirt ribbon road_sign sign single_braid skirt standing tamada_(girls_und_panzer) tank traffic_light uniform video_camera yellow_skirt rating:s score:12 post #3567248](/cdn_image/preview/2f/fc/2ffc94e83da1891997cee8195f7daa25.jpg)
The O-I Super Heavy Tank was a prototype tank developed by the Imperial Japanese Army in World War II. The vehicle featured a multi-turreted design and an immense weight of 150 tons, second only to the Maus. While stronger than any available Japanese tank at the time, it's immense weight and size made it unfit for the Pacific theater, with only one turret-less prototype being developed for trials.
While only the O-I was produced, this tag can refer to the variety of paper (albeit later confirmed fake) projects related to the O-I popularized by World of Tanks, including the O-I Exp., the O-Ni, the O-Ho, etc.