Green’s Dictionary of Slang

transformer n.

[the toy Transformers, popular in the 1980s, which appear to be one thing, e.g. a car, but can be changed into another, e.g. a robot]

1. (US black gang) a spy.

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[US]L. Bing Do or Die (1992) 122: He a transformer in my ’hood.

2. (N.Z. prison) one who shifts their allegiance between races or prison gangs.

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[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 193/1: transformer n. lone who seeks to identify with, or pass as a member of, an ethnic group different from his own. 2 an inmate who regularly changes his gang affiliation so as to be in accordance with the gang currently in majority in the prison.