Thomas D. Butler, taxidermist and attendant at the South African Museum, was the son of the soldier and taxidermist Joseph Butler. He was appointed as taxidermist in 1875, following the death of his father who had held that position for 16 years. His work was satisfactory as far as Curator R. Trimen* was concerned, but he was probably too careless for a careful mammalogist like Trimen's successor, Director W. L. Sclater*. He therefore resigned his position in May 1896. However, he returned to the museum in January 1899 as an attendant, rose to head attendant and held this position to his retirement in 1921.
Butler donated some insects from around Cape Town and Caledon to the South African Museum in 1893, followed by more insects from Caledon the next year. He is again mentioned in the museum's Annual Report in 1905, having donated various insects from Johannesburg. In 1908 he donated ants from Kimberley, and some arachnids. During that same year he also presented to the museum a collection of 71 birds, representing 37 species, from the Modder River, a nest of the white-browed sparrow-weaver Plocepasser mahali, and some hares and steenboks.