Tobar is one of Malcolm's people. When he was eight he was driven out of his village because he was considered a 'freak' due to his size, his only friend was a Border Shepered who was killed defending Trobar when he was driven out. Malcolm found him crying over the dog and together they buried it. Malcolm then took him under his wing.
Though Trobar appears threatening, he is really gentle; as shown by the way he treats Shadow, Will's dog, (whom he named.) The two develop a close relationship. Later, He becomes angry towards John Buttle after Will tells him how Shadow came to be injured. He makes himself a club from a branch and fights Buttle in the Battle for Macindaw, giving Horace Altman the time he needs to grab his sword and defeat Buttle.
Trobar is injured in the fight, nearly dying, but is soon healed by Malcolm. He is upset he hears Shadow is about to leave with Will. Will feels pained, and lets the Shadow stay in Grimsdell wood with Trobar, much to the giant's delight. In parting, Will tells the giant: "If she [Shadow] ever has puppies, I want the pick of the litter."
Later on, Shadow does have puppies. Trobar gives Will one named Ebony. These events are recorded in Halt's Peril, after Malcolm heals Halt and is then escorted back to his home in Grimsdell by Will.
In the Lost Stories he and Malcolm go to Will and Alyss' wedding, much to Will's delight.
Trobar is massive, towering over even Skandians, his large size makes people think that he would be a violent person but he isn't really, however in book six he goes for Buttle after Will tells Trobar how the brigand attacked Shadow.
He is very strong, however he is quite clumsy and is not a warrior. When Will and Horace stormed Macindaw, he showed up with a club made with a branch.
Trobar has a speech difficulty and can't speak properly due to a cleft palate deformation but still manages to communicate with others.
When Malcolm is tending to his wounds, he mentions that he lost enough blood to kill 2 men. Will says that he must've had enough for 3. This shows Trobar's enormous size.