When Jacko Tanner was a student at Thames University, he was friends with fellow students Courtney Ross and Sandy York. He also knew Brian Braddock, but they were hardly friendly to one another. Jacko was something of a bully and often openly hostile to Brian for unknown reasons and he was often seen with other friends, Charley and Tommy, when he was either bullying or taunting Brian. Part of the bad feelings between them may have stemmed from the fact that Jacko was interested in Courtney as a girlfriend, but she was more interested in Brian.
Jack often hung out at a local pub called the Flying Finish that was owned by Dora. One night at the pub Jacko had just insulted Brian to Courtney, much to her annoyance. Then Sandy began questioning Jacko's intelligence, but he annoyed Courtney as well.
After the bombing of Braddock Manor, it was assumed that Captain Britain and Captain America had perished in the explosion. Courtney turned to Jacko for emotional support as lie in state at St. Paul's Cathedral. However, his callous behavior towards the situation caused Courtney to become cross with him and slapped him in the face. Jacko then became angry and told to get her "milksop chum" Brian to hold her hand.
He became inadvertently involved in a number of Captain Britain's early adventures, most notably when he seized control of Lord Hawk's robot bird and tried to capture Captain Britain with it in order to impress Courtney. Captain Britain freed himself from the bird's grasp as Jacko used the control panel to slam the hero into the ground and knocked him unconscious. Captain Britian awoke just in time to see Jacko racing towards him intent on unmasking him, however, Commander Hunter of S.T.R.I.K.E. arrived in time to take Captain Britain away for medical treatment.
Jacko, Courtney and Brian were amoung the students from Thames University that traveled to Scotland to take part in a scientific investigation of the Loch Ness monster and he helped stop the Lurker from Loch Ness.
Powers and Abilities
No known paranormal powers
Immature and jealous personality