Tzvi was born on July 4,1925 in Biała Podlaska to Moshe and Genendal, traditional and Zionist family. His father decided to make aliya. In 1932, he went alone to make things ready for the family, which followed three years later, settling in Tel Aviv’s Neve Zedek neighborhood. Tzvi studied in Tachkemoni School and the Max Pine Technical School. He was part of the religious division of the Scouts.
In 1937, he joined Beitar; in 1938, as the riots climaxed, while the Hagana was exercising restraint, he joined the IZL. All IZL members were expected to leave Beitar, so Tzvi joined Young Maccabi. In 1941, after the split, he joined Lehi.
His nom de guerre was Benny, but he also was known by his name in reverse, Yaavetz. He joined the youth cells and underwent training in firearms and provided security for the underground radio station, when it was operational. At the height of the persecutions, the commander of his cell disappeared, and for a while he was out of touch. In order not to be left with nothing to do, Tzvi and two friends joined Palmach. He was assigned to Company C, in Ashdot Yaakov. A year later, his comrades told him that the connections to Lehi had been restored. They left the Palmach and returned to Lehi, now well-trained in firearms and field maneuvers.
Tzvi was, from then on, tracked by the Hagana, and even was interrogated about his ties to IZL (!). In 1944, he was arrested, presumably due to informers, and he spent a year detained in Latrun. Once he was released, he returned to underground duty, assigned to the Intelligence Department (Department 6). He was in charge of connections to Jewish policemen and officers, transferring information to the movement, including from those in the most senior positions. Starting in 1944, he worked for the HaArgaz company of the Histadrut, and like all its members, he was a Hagana member, in addition to being in Lehi. In the Hagana, he was assigned to Hish in the suburbs.
When the War of Independence broke out, Tzvi was put on full duty with Hish in the suburbs, which eventually was organized as Battalion 53 of the Givati Brigade. He fought in all of its battles in Har Tov and the southern front. He completed his military service with the rank of first sergeant and went back to HaArgaz, until he retired in 1988.
In 1952, he married Yehudit Wildorf. They had two sons, Eitan and Roni, and numerous grandchildren. He practiced painting and woodcutting by burning.