- "Oh! I get it. You guys don't have facial transmogrification technology on this Earth."
- "No. We certainly do not."
- —H.R. Wells and Caitlin Snow[src]
A facial transmogrification device is a device created on Earth Nineteen that allows people to take on the appearance of other people.
To extract a source of energy from A.R.G.U.S., Barry used the device to impersonate Lyla Michaels, the then-owner of said research organization, since the real Lyla denied him the source of energy. "Lyla" brought Leonard Snart and claimed to bring him to the Task Force X. When "Lyla" could not answer a password, Barry stopped using Lyla's likeness and knocked out the agents.
H.R. used the transmogrification device to save Iris West from Savitar by switching appearances with her and fooling Killer Frost (then-supporter of Savitar) to realise Iris-as-H.R.. When Savitar apparently killed Iris, the dying H.R. restored his and Iris' real appearances to reveal Barry and company that he sacrificed his life.
A.R.G.U.S. was prepared to imposters using this sort of devices by requiring DNA tests. When Clifford DeVoe used Ralph Dibny's powers to impersonate Diggle, he was required to give his DNA. DeVoe killed the agents with all the other powers he stole.