Green’s Dictionary of Slang

(drugs) orig. an opium addict, a drug addict.

1922		E. Murphy Black Candle 114: The Chinese here still furnish a large percentage of the ‘hoppies’.
1924		G. Henderson Keys to Crookdom 306: Lowest of all is the ‘snow bird.’ Even the ‘hoppies’ themselves look down on a user of cocaine.
1932		Cab Calloway ‘Minnie the Moocher’s Wedding Day’ 🎵 They said a hundred thousand hoppies / Went over to China picking poppies, / They’re gonna put them all in one bouquet / For Minnie the Moocher’s wedding day!
1949		Monteleone Criminal Sl. (rev. edn).
1953		W. Brown Monkey On My Back (1954) 89: ‘I ain’t no hoppy. Just look,’ he held out his arms. ‘Do you see any holes in me?’.
1959		B. Hecht Sensualists (1961) 93: Oh what a bitch she was. A crazy hoppie.
2009		Metro (London) 26 June 5: The happy hoppies and the poppies.