The Toros had been modestly successful on the ice since moving to Toronto before the start of the 1973–74 season and had drawn fairly well by WHA standards. However, onerous lease terms at Maple Leaf Gardens led owner John Bassett to move to Birmingham.
After the initial move to Birmingham, general manager, Gilles Leger coached the team for a few games until Pat Kelly was brought in to coach the bulk of that first 1976–77 season in Birmingham. In the 1977–78 season, former Minnesota Golden Gophers coach Glen Sonmor was hired to lead the team as head coach and general manager. Sonmor organized a very physical and aggressive team that was the most penalized in the league for their rough play. They set a team record for penalty minutes that stood for decades in all of professional ice hockey. They were often called the "Birmingham Bullies," a play off of the nickname "Broad Street Bullies" that the Philadelphia Flyers had earned years earlier, whose own record for penalty minutes the Birmingham Bulls had broken. This new approach to being the bullies debuted on a Thanksgiving Day game in Birmingham against the Cincinnati Stingers. That game started with ten players in the penalty box within the first minute of play. The Bulls won 12–2 and was dubbed by the newspaper as "The Thanksgiving Day Massacre." This was the only one of the three WHA Birmingham Bulls teams to qualify for the WHA playoffs. Facing Bobby Hull and the Winnipeg Jets, who went on to win the championship, they were eliminated in the first round. During Sonmor's tenure as general manager, he successfully negotiated the first "cross-league" player trade with the NHL in a deal with the Detroit Red Wings.
John Brophy, who later went on to coach the Maple Leafs, had joined head coach Glen Sonmor as an assistant for the second year in Birmingham. Brophy became head coach in the 1978–79 season when Sonmor joined the Minnesota North Stars. His team finished last in the league, but was in the middle of a youth movement in transitioning from being overly physical to highly skilled and was known among the fans as the "Baby Bulls". Wayne Gretzky was heavily recruited by Birmingham Bulls owner John Bassett to be part of the youth movement. Bassett wanted to confront the NHL by signing as many young and promising superstars as possible and saw Gretzky as the most promising young prospect. Although Bassett failed to sign Gretzky, the Bulls included several future NHL stars at the beginning of their professional careers such as Rick Vaive, Michel Goulet, Rob Ramage, Pat Riggin, Craig Hartsburg, Gaston Gingras and Rod Langway, as well as a 36-year-old Paul Henderson. Even though his team was the only one in the league not to make the playoffs, Brophy was awarded the Robert Schmertz Memorial Trophy as the WHA's coach of the year.