"Fohrok", or Fake Bohrok, were a breed of false Bohrok created by the Nynrah Ghosts for the Brotherhood of Makuta. With their blue and yellow markings, they resembled a Pahrak. They served in the Brotherhood's army until the Toa Hagah destroyed them when the Toa rebelled against the Brotherhood. Unlike Bohrok, they didn't use Krana. The tribe of Nynrah Ghosts who built them were executed by Dark Hunters hired by the Makuta upon learning that they were sabotaged.
"Fohrok" is a non-canon fan-made name, but the machines themselves are canon.
Fohrok were exact duplicates of Bohrok found in a nest by a member of the Brotherhood of Makuta.