stooges

noun
  1. 1

    One who knowingly allows himself or herself to be used for another's profit; a dupe.

  2. 2

    A straight man.

  3. 3

    A secret informant for police.

  4. 4

    A confederate; a person who is secretly working for the researcher, unknown to the study participant.

Source: https://en.wiktionary.org/wiki/stooge, https://en.wiktionary.org/wiki/stooges