Copycat

wiktionary

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From copy +‎ cat(“former derogatory term for a person”).

etymonline

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copycat (n.)

also copy-cat, derogatory term for one who copies another or another's work, by 1884, American English, probably at least a generation older, from copy (v.) + cat (n.). As a verb, "to slavishly imitate," from 1932. Related: Copycatted; copycatting.