Gunnar (renamed as Justin in the english version) is the main antongoist in the movie Terkel in Trouble.
Gunnar is a animal activist who starts as a teacher in Terkels class after the regular teacher is killed in an accident. Near the end of the film, Terkel tells him that he thinks Jason wants to murder him for accidentally causing his sister Doris to commit suicide after he rejected her as a girlfriend. After telling him everything, Terkel proceeds to call Jason in order to tell him that Gunnar knows everything and that he can't do anything. However, Terkel soon discovers that the ringtone comes from Gunnar's pocket. Gunnar then reveals that he is going to kill Terkel just because he accidentally killed a spider while sitting on it the first time they met. He tries to stab Terkel, but Terkel escapes and tries to call his parents, but they doesn't listen to him and hangs up. He also tries to get Stewart to drive him into town, but fails. After Terkel is distracted when Gunnar calls his telephone, Gunnar appears from the shadow and hits him in the head. He then proceeds to strangle Terkel to death, but Jason (who understod what was going to happen after talking to Sten and Saki), saves him in the last second by knocking Gunnar out with his iron bar. However, Gunnar soon wakes up and tries to attack Terkel, but Jason throws his iron bar to Terkel, who tries to hit Gunnar with it, only to be easily blocked. Just as Gunnar is about to kill Terkel, Jason attacks him and yells for Terkel to get the iron bar, but Terkel accidentally slips on the body of Gunnar's pet Liselotte, causing him to drop the iron bar. After a wild fight, Terkel manages to retive the iron bar while Jason escapes from Gunnar. As Gunnar is walking thowards the two boys, Terkel tries to defend them using the iron bar, but Gunnar simply kicks the iron bar high into the air. He then starts using taikwando, grabs two knives and is about to kill the two boys when his head gets impaled by the pipe he kicked up himself, killing him.
However, just before the credits starts, Gunnar moves his eyes, raising the question if he really died.