McCulloch was born in Shepherd's Bush, West London, England. He started out with local band The Avro Boys, who became Tony Craven & The Casuals in the late 1950s. In 1960, The Casuals linked up with new singer Frankie Reid and McCullough remained with the group until October 1962. During his time with Frankie Reid & The Casuals, one of the band's drummers was Mitch Mitchell.
McCullough and drummer Derek Sirmon next joined Screaming Lord Sutch & The Savages and stayed until May 1963. In 1964, McCullough and Sirmon joined Woking band, The Plebs, who recorded a lone single. During mid-1966, McCullough worked briefly with The Carl Douglas Set.
McCulloch and Briggs started a duo career. In 1969 they released the album Wings of a Man. In 1971 McCulloch was the bassist on Reg King's solo LP. In the 1980s Danny worked as a psychiatric nurse in the south Lincolnshire psychiatric hospital Rauceby in Sleaford Lincolnshire
In 1993 he put together a new Animals group, which rerecorded the old hits and a few others. In 1995 he recorded a second solo album, Beowulf. In the 2000s he was touring with a new Animals formation, called Animals and Friends.