- "You want it in tummy or face?"
- ―Behem, offering his victims the choice of where he will punch them[src]
Behem is a Rephaim bully from Gath, who harbors a Sidon-like obsession with getting revenge on Branan. As a child, Behem enjoyed intimidating the other children of Gath to the point where they pleaded with Branan to put a stop to the abuse. When Branan stands up to Behem in the midst of his harassing other children, Behem punches Branan in his rock-hard stomach, which causes injury to Behem's hand. Seeing their antagonist thus stunned with pain, Branan's friends give Behem a wedgie, which throws him off balance enough for him to fall into the nearby sewage trough.
Branan puts his foot on Behem's chest and makes him swear that he will never go around terrorizing the children of Gath again, which he promises to do. Astonishingly, Behem and his mother arrive at Branan's house later that evening to demand an apology from Branan for "picking on" poor four year-old Behem. Branan, with apparent sincerity, expresses regret over his actions that afternoon, and Branan and his mother laugh heartily over the nerve of the town bully demanding an apology from one of his victims.
Branan's attempt to smooth things over was apparently not enough to assuage the anger inside Behem's heart. Ten years later, while Branan is in the process of trying to rescue his grandfather Manoah from the Philistine outpost in Ekron, Behem demands a duel to the death with Branan. Having no time for such foolishness, Branan rides away to save his grandfather, but Behem tries to hit Branan with a rock using a sling. Fortunately, Behem's aim is completely off, and his rock ends up ricocheting off a boulder and hitting himself in the head.
Doggedly insistent on getting his rematch with Branan, Behem stalks Branan to Sidon's campsite on the road to Ashkelon. In the midst of Branan's battle with Sidon, Behem clubs Branan over the head and begins fighting with Sidon over who gets to kill Branan. During their brawl, Sidon hurls a spear straight towards Behem's head, but Branan uses Behem's bat to shield him from the spear.
Despite Branan's merciful act of saving Behem's life, Behem pushes Branan aside and continues to scrap with Sidon. When Behem runs into a tree branch and gets knocked out cold, that's the last we hear of the giant from Gath.