Hilmer N.E. Skoog, a Swedish naturalist, started his career as an errand boy at the Naturhistoriska Museet (Natural History Museum) in Gothenburg, Sweden, in 1884. He was promoted to assistant curator in 1900 and to curator in 1904, a position he held until his death in 1927. In 1909 he accompanied Nordenskiold's expedition to Greenland to collect for the museum.
On 30 November 1911 Skoog left Sweden on his way to Cape Town, planning to travel on a whaling ship from there to investigate the Crozet Islands, in the southern Indian Ocean. However, he was delayed by bad weather and when he reached Cape Town in January 1912 the whaling boat had left. During the next three months he undertook collecting trips in the South Atlantic and along the southern Cape coast (off Cape Infanta, St Sebastian Bay, Cape Barracouta, and Walker Bay), and then established his headquarters at Franskraal, a few kilometres inland from Gansbaai, Western Cape. In May he collected marine invertebrates and the terrestrial fauna, including many birds and bird parasites, in the region around Franskraal. The next month he left for Port Alexander (now Tombua) on the coast of southwest Angola. There he continued his excursions, both along the coast and inland, until November. At some stage he also collected molluscs in Namibia. After returning to Franskraal and some more collecting, he left for Sweden where he arrived in May 1913.
Skoog published four popular articles in Swedish journals during 1918-1919 on his work in southern Africa, including one on his adventures while hunting buck at the Cape. His extensive collections all went to the Gothenburg Museum, where the following groups were studied and described by various specialists: Reptilia and Amphibia (Alexander, 1916), Tunicata (Michaelsen, 1923), Ophiuroidea (Koehler, 1923), Bryozoa (Marcus, 1923), Mollusca (N. Odhner, 1923), Pantopoda (Loman, 1923), Sipuneulida (Fischer, 1923), Crustacea Podophtalmata (T. Odhner, 1923), Isopoda and Amphipoda (Stebbing, 1922), Copepoda (Wilson, 1923), Polychaeta (Fauval, 1923), Cestoda Tetrabothridia (Nybelin, 1916), Nematoda Oxyuridae (Allgen, 1925), Octactinia (Molander, 1929), and Hydroidea (Jaderholm, 1923). The Desert Plated Lizard, Gerrhosaurus skoogi (Family Gerrhosauridae), which occurs in Angola and Namibia, was named after him, as was the South African marine mollusc Adinopsis skoogi.