Janklow was an enlisted Starfleet engineer assigned to the USS Defiant in 2372.
While caught in the atmosphere of a gas giant that year, Janklow was among the engineers assigned to repair damage caused to the Defiant by the Jem'Hadar. During the repair work, Chief Miles O'Brien ordered Janklow to get him a dualitic inverter from the ship's cargo bay and Janklow answered: "Right, Chief."
En route, Janklow was caught in an explosion on Deck 2, and was thrown to the floor from an inward rush of nitrogen gas. (DS9: "Starship Down")
Janklow was played by stunt actor Tom Morga, who received no credit for his appearance although he spoke two words.