Frogg attended
Frogner School, where his classmates included
Johan Borgen. In 1921, the two friends approached
Halfdan Christensen, who was manager at the
National Theater in
Oslo, to be employed as actors in the ensemble. Frogg made a positive impression, and he debuted in the role of the priest's son Benedikt in
Nini Roll Anker's
Kirken in the spring of 1921, and as the young writer Falk in Ibsen's ''
Love's Comedy'' at the
National Theater in
Bergen. He returned to the National Theater in 1928, playing major roles in classical and modern plays. From 1930 to 1933, Frogg was engaged at the
Oslo New Theater, where he performed demanding roles, including the title role in
Marius in 1931, a play by the French writer
Marcel Pagnol. The following year, the theater staged Pagnol's
Fanny, again with Frogg in the role of Marius. He also played Captain Stanhope in the
R. C. Sherriff's ''
Journey's End from 1928, about four days in the trenches during the First World War. Back at the National Theater in Oslo, he had the lead role as Dominique in Domino
, together with Gerd Egede-Nissen. After the 27th performance, in 1934, he died after falling from the veranda of his apartment on the eighth floor of a dormitory building at Frogner plass
. He was dead when he arrived at the hospital. He left behind a slip of paper with the inscription G.E.N.I.
, which may have stood for Gerd Egede-Nissen Ingebrigtsen''. ==Family==