Hornibrook in A Bibliography of Queensland Verse (1953) asserts that T. P. Lucas used the pseudonym 'Achilles Douglas' but this claim is discredited by research into Lucas undertaken by Dr Bill Metcalf in 2005. After examination of the only traced publication by Achilles Douglas, a polemical work entitled Devils Abroad and How to Fight Them (Brisbane: Davison & Metcalf, 1888), Metcalf concludes that the two are clearly not the same but has been unable to answer the question as to who he/she really was.
Metcalf describes his search in these words:
'Firstly, I started with the obvious hypothesis that Achilles Douglas was really Achilles Douglas. Genealogical searches, using the usual Google, IGI and FreeBDM internet methods, plus internet checks of available census records from the period turned up several people with Achilles Douglas as their name or part of their name but none of these people were anywhere near Australia nor even of the appropriate time period. I also searched Post Office Directories and BDM records for New South Wales, where I believe 'Achilles Douglas' lived, Queensland, Victoria and South Australia for the 1870 to 1900 period but found neither an Achilles Douglas nor a Douglas Achilles.
I looked for any records of the Brisbane publisher of Devils Abroad and How to Fight Them, Davison & Metcalf, in the hopes that they might identify their author but was unsuccessful.
I conclude that while Achilles Douglas was certainly not a pen name for Dr Thomas Pennington Lucas, it was a pen name for someone, but for whom I do not know. The language certainly suggests that Achilles Douglas was a man rather than a woman. I also believe that the person lived in Sydney during the 1880s.'