There aren't many solid biographical facts on this character; for example we don't know his first name. He was introduced in the second season in the episode "Partners" and became MacGyver's nemesis, and the most frequently recurring villain, appearing seven times in all.

In his first appearance in "Partners" we see Murdoc in two different time periods; the present (1987) and seven years before (1980). It was established that Murdoc was an international assassin, who specialized in elaborate disguises of appearance and voice (including masquerading as a woman, so adeptly that he aroused Mac's chivalry) and was especially skilled at building bombs. Murdoc had been known to the DXS for five years prior to 1980 (At some point during this time Pete Thornton had almost captured him in Lisbon.) As part of "the game" Murdoc would send photographs of his victims at the moment of their deaths to the DXS.

The result of the 1980 encounter was Pete and Mac driving Murdoc into a building just before it was demolished. For unknown reasons Murdoc waited for seven years to return for revenge. Though he had some scarring on the left side of his face, he seemed otherwise recovered from being squashed by a building. It was his intention in 1987 to lock Mac and Pete (and Jack, who failed to show) into a truck and blow them up. In the end, however, it was he who was 'blown up' when he dropped a lit piece of dynamite in the truck cab.

For his next attempt at revenge in third season's "Widowmaker" Murdoc, now even more seriously scarred on the left side of his face, cornered Mac and his co-worker Nikki on a mountain-side. We learned little that was new about the character in this episode, except that he's extraordinarily quick. In the time it took Nikki to carry the groceries into the cabin and tell MacGyver he was being a jerk, Murdoc mined the road coming in, sliced Mac's tires, rigged a bomb and a winshield wiper sign on Nikki's car, got out a flamethrower and snuck into the cabin's kitchen and taped up three pictures. However, things turned out for him no better in this attempt. He ended up cutting his own climbing rope and falling off this very tall mountain.

Miraculously he survived the fall and returned a little over a year later (recovery time is much improved from the original seven years, albeit he's confined himself to a wheelchair for much of the episode and was apparently wearing a metal brace on his left leg). In a very overelaborate "Phantom of the Opera" scheme, Murdoc staged a Rock Musical, "Cleo Rocks" and arranged for Mac's good friend Penny Parker to star in it. He posed as a Frenchman, Jacques La Rue, director and composer of the musical.Murdoc apparently is a very accomplished keyboardist and composer. Again his plan, which included hydraulics, a fiery pool and not enough back ups, failed. Mac took exposed wires and touched them to the metal on Murdoc's left leg, electrocuting him and causing him to fall into the pool. It is interesting to note that in this incident Murdoc envinces a considerable respect for MacGyver and seems intent on proving that MacGyver is no better than him, whereas before he was just trying to kill him.

Dead? Murdoc, of course not. He wriggled out of the pool through a broken sewer pipe and when we saw him again in "Halloween Knights" he was none the worse for wear. In fact he seemed to have recovered all use of his limbs and have visited a plastic surgeon to repair the cumulative damage to his face. In this episode we learn much more about him. He worked for HIT, Homicide International Trust, a sort of distribution center for murder contracts and other nefarious deeds. The leader of this organization, Nicholas Hellman, was Murdoc's mentor and taught him everything he knows. However in Halloween of 1989, Murdoc is trying to retire over the objections of HIT. In order to lure him in to be killed, Nicholas has kidnapped Murdoc's sister, Ashton. MacGyver mentions a DXS file which says that Murdoc has no living family. Though Murdoc does not detail the exact circumstances it is apparent that he and his sister were separated at an age where she was too young to remember him. Though he has kept track of her, and implies that he has been supporting her monetarily, it is without her knowledge. The brother and sister do not share the same last name. Her name, probably from adoptive parents, is Cooke. We also discover that Murdoc has a phobia about snakes.

In this episode Murdoc makes the leap from respecting MacGyver to trusting him. Mac, inexplicably, returns the sentiment, and they cooperate to rescue Ashton. Murdoc doesn't fare much better in this incident. Instead of running with Mac and Ashton, he sticks around to toss a grenade at his mentor. Mac and Ashton, (who remained unenlightened about Murdoc's identity as her brother) believe he is dead. At the end Murdoc leaves Mac a message to announce his continued existence and deliver the goods on HIT.

Murdoc's next appearance was in MacGyver's dream of "Serenity" in 1990 and hence doesn't count towards any biographical information.

In early 1991 Murdoc, returned in "Strictly Business". Apparently unemployed, he approaches HIT (still functioning, but with a completely new board) for his old job back. They will only take him back provided he can kill MacGyver. He agrees and then arranges an almost-hit on MacGyver, but pulls back at the last second and rationalizes that this evens the score and makes Mac fair game again. Note that Murdoc has graduated from his trademark still photography to the more modern Camcorder. At this time Murdoc tells Mac that Ashton has died in an avalanche in Switzerland. This, perhaps more than a need for money, may have motivated Murdoc's return to HIT after his "retirement".

In "Strictly Business" Murdoc makes several attempts on Mac's life. Mac survives his car being blown up and is rescued at the last minute from being shot when the little girl, Amy, distracts Murdoc. The final attempt bore a strong resemblance to the test sequence in "Cleo Rocks." A series of obstacles, with the woman tied up as the goal, culminating in hand to hand combat. This time a dropping mine elvator pulls Murdoc down a shaft, supposedly to his death, in the river far below. As usual no body is found.

Recovering in a mere six months this time, Murdoc returns in the seventh season's "Obsessed". Despite the authorities claiming that Murdoc is dead, MacGyver is convinced he's alive. Right, as usual. Mac has to try and find and stop Murdoc, by himself. Any previous mutual respect is thrown out the window, as Murdoc seems more unbalanced than usual. Murdoc, rejected by HIT because he failed to kill Mac and is "over the hill", makes the, for him, unusual move of teaming up. His ally is a nasty South American dictator, Pablo Dellasauro. Mac foils their plan to shoot a missle at the little country Pablo is trying to re-take. Eventually, just before Murdoc gets around to shooting MacGvyer, the dictator orders Murdoc shot. Apparently the soldier was not using silver bullets. Murdoc escapes in a jeep and then goes over a cliff while trying to run over Mac. The jeep burns. The body is not found. But just so Mac doesn't worry this time, Murdoc gives him a call, laughs maniacally and hangs up.

Name: Murdoc, NFN
Age: Undetermined; approximately the same as MacGyver
Place of Birth: United Kingdom
Family: No living relatives. Sister; Ashton Cooke, deceased
Profession: International Assassin. Bomb and weapon expert. Master of disguise, skilled mimic. Occassionally employed by HIT (Homicide International Trust. See file 439000XO), also freelance
Wanted In: Practically every country on Earth
Friends: You must be joking
Hobbies: Photography, Musical composition, amateur theater, truck driving, mountain climbing, cooking.
Dislikes: Having buildings drop on him, fire, falling off mountains, production bills, snakes, demanding employers, unreliable South American dictators, Peter Thornton, MacGyver, MacGyver, MacGyver.
Favorite Color: Black
Favorite Actress: Penny Parker
Oustanding characteristics: Short; Difficult to kill; Very, very determined; Unlucky (or lucky depending on your POV)
Last known whereabouts: A phone booth at a Denny's on the Pacific Coast Highway

"That's Murdoc; He's not your normal professional killer." -- MacGyver The Widowmaker