Gerwig was trained as a professional wrestler by Fred Bozack and
Ralph "Ruffy" Silverstein, debuting in 1954. As a singles heel through the sixties, he was a top-of-card fixture battling well-established crowd favorites such as
Mark Lewin,
Spiros Arion,
Tex McKenzie,
Dominic DeNucci, and
Mario Milano. Enormous numbers from Australia's nascent ethnic community turned out to support Arion, Denucci, and Milano, and Kox risked riots at every appearance. On February 21, 1967, he and
"Iron" Mike DiBiase defeated
Pedro Morales and
Ricky Romero to win the
Worldwide Wrestling Associates'
WWA World Tag Team Championship. He defeated Buddy Rogers to win the MWCW North American Championship in March 1968. Fans longed to see the brainbuster deployed on the side of good, and this boon was granted in 1971 when the Killer turned into a babyface in a nationally televised mea culpa - he pledged to change his ways on a solemn promise to his dying mother. This created much heat in the already booming Australian wrestling promotion, where the fixture was an ongoing television "war" between the good guys referred to as the "People's Army" (Lewin, Curtis, Arion, Milano and visiting faces from overseas) and the "mercenary soldiers" managed by Kentucky biker / preacher Big Bad John. The turning of the tables saw the erstwhile Killer create great excitement in tag matches against his former heel comrades
Abdullah the Butcher,
Brute Bernard,
Dick "The Bulldog" Brower,
Tiger Jeet Singh,
Waldo Von Erich and Japanese heels like
Mr. Fuji and the Tojo Brothers (
Hiro "The Great" Tojo and
Hito Tojo). He lost to Johnny Weaver on May 4, 1973, in a
hair vs mask match while working as the "Masked Menace". He won the
Florida Brass Knuckles Championship by winning a tournament, and also defended the title against
Rocky Johnson and
Steve Keirn. In February 1978, he defeated
Dusty Rhodes to win the
NWA Florida Heavyweight Championship. At a wrestling show later that year, Kox was wrestling a match when a fan started to repeatedly hit him with an umbrella. Security got involved and detained the fan, but instead of kicking the fan out of the show, Kox requested that they bring him into a backroom with the door locked. He allegedly requested that security not let him out until it was alright doing so. Security took the fan to a back room and locked the door. After Kox's match ended, he told security to open the door and he went in. Five minutes later, Kox walked out of the room and the fan was found lying on the floor, covered in blood and was knocked out unconscious. In the wrestling profession, Killer Karl Kox was always a popular figure for his humor, behind-the-scenes jokes and inventiveness in furthering the promotion ("the greatest gimmicks man in the business" said one colleague). His grudge matches were well-calibrated, building through a series of disqualifications and non-decisions through run-in interference, and often climaxing in a conditional match in which "the loser packs his bags and leaves town." This saw off one or the other of the combatants as they travelled to fulfill other promotional runs in other countries; battle would be re-joined next season when the participants returned for another profitable run.
Dick Murdoch once listed a number of people he had supposedly defeated and put out of wrestling, including a midget wrestler from the 1940s (few people caught the joke reference) and also listed on Herb Gelwig, (who was of course Killer Karl Kox with whom he teamed several times and was still quite active.) On October 9, 1979, he defeated
Bob Armstrong to win the vacant
NWA Georgia Heavyweight Championship. Kox was cheered in Australia for one of the few times in his life when he faced the team of Abdullah the Butcher and Bulldog Brower. Among Killer Karl Kox's famous matches in Australia, his feuds with man-mountain Haystacks Calhoun usually involved the insinuation of foreign objects into the proceedings by Kox. At the end of one season, Kox "left Australia for medical treatment in the states" when, in a
strap match with Bulldog Brower, his eye was nearly removed (the wound was unbandaged to show the television audience). A headline making event was when a television match for the
IWA World Heavyweight Championship against
Spiros Arion was declared ended due to time limit by well-loved commentator
Jack Little. Kox responded by delivering the
brainbuster to the unfortunate Little, who was hospitalized and required to call matches the following month in a
neck brace. Kox retired from professional wrestling in 1983. He made his final wrestling-related appearance at VCCW Quest for the Crown II in August 2011, taking part in a meet and greet as well as later presenting the championship to Scot Summers. == Death ==