Thomas Murphy, played by Christopher Fairbank, is a character in the film Alien³.
Murphy is an inmate who owns Spike, the dog that would become the host for the Alien shown in the film. Murphy mistakes the burns on Spike's face - left by a Facehugger - for another inmate's handiwork.
While cleaning the vents searching for Spike, Murphy stumbles upon the Alien's shedded skin; the Alien blinds him with acid, and Murphy stumbles into a ventilation fan which tears him apart.