Injun Joe is portrayed by Aboriginal Canadian actor, Eric Schweig.
Injun Joe first appears in the opening of the film as he makes his way across the town of Hannibal on the stereotypical dark and stormy night. He arrives at the town hospital, where he accepts a job from Doctor Robinson, who at first says it pays two dollars. However, he changes his mind when Injun Joe threateningly unsheathes his knife and puts it at his throat, asking for three dollars - unless the doctor thinks he deserves more (meaning a blade in his throat). After that, Injun Joe then turns and steps out into the night.
Later on the next night, Injun Joe is with Doctor Robinson and the town drunk, Muff Potter, on a grave robbery. After they uncover the coffin and corpse of One-Eyed Murrell, a chest rolls out. Doctor Robinson grabs the small box, and orders Muff and Joe to put the coffin back and cover up the tracks as he walks off. Injun Joe, however, tries to pry the box away from Robinson, and punches him in the face, until he falls to the ground while Joe grabs the box. He opens it, and discovers the map to Murrell's lost treasure. After Muff helps Robinson up, he looks at the map, and shouts in amazement, "By glory, we're rich!"
Just then, the greedy Robinson grabs a tombstone and tries to pummel it into Injun Joe as he screams in avarice, "It's mine!" But he misses, and hits Muff Potter instead, knocking him unconscious. Incensed by the assault, Injun Joe punches Robinson three times, until he falls back to the ground against the fence. Injun Joe unsheathes his knife, and threatens to stab the sniveling doctor. But he puts his knife away, turns to Muff, and takes his knife. There he returns to Doctor Robinson, and stabs him three times, until he is dead.
Unbeknownst to the three men, Tom Sawyer and Huck Finn, who were trying to remove warts by taking a dead cat to the graveyard at night, saw everything. But as they leave, Injun Joe hears them, and pursues them, but they disappear into the mist. Joe then finds a green marble in the grass, and believes it belongs to the kids. Luckily for Tom and Huck, they were not seen entirely, keeping them safe... at least for now.
As part of Joe's plan, Muff is framed for Robinson's murder. He tries to ask Injun Joe to vouch for him, only for Injun Joe to lie about what really happened, saying that while he was passing last night through the graveyard, he saw Muff and Robinson digging up Murrell's grave, and that he saw Muff stab the doctor. Muff, remembering last night's event, tries to tell the truth, but Joe dismisses it as "drunk-talk", and there is no Murrell's Lost Treasure or the map to it.
Tom and Huck, despite an oath they signed to never tell what they witnessed the other night, go on a search for Injun Joe's map - the only evidence for Muff's innocence. The only problem in retrieving the map that it is in Joe's pocket. The duo find him at the tavern with his partner, Emmett, through a window. As the villains talk, Joe shows to Emmett Tom's marble, saying that a boy dropped it, and that he will kill him for witnessing the murder.
At the same time, as Tom discovers Joe has taken his marble and might come after him, he and Huck accidentally cause the box they are standing on to topple. After they tumble, a plank of wood falls straight through the window, almost blowing the duo's cover. Injun Joe and Emmett, who were nearly hit by the board, quickly rush out to find the person they think did it. But there is no one. Emmett says that it was probably a drunk that smashed the window. Joe jokingly replies that it wasn't Muff Potter. Emmett laughs at the joke, and says that "the only stumbling he's gonna be doin' is at the end of a rope". Injun Joe walks off to the harbor, and takes a canoe to the other side of the river. Tom and Huck follow him in Muff's canoe.
The next morning, Tom and Huck make another attempt to steal the map, by covering themselves in mud, so they will not be seen. They find Injun Joe drunk asleep, and this gives the boys their chance to steal the map without being noticed. But once again, Tom blows his cover by sneezing just as he is a few centimeters close to the map. Injun Joe wakes up, and looks around to find the person who woke him up, while Tom and Huck make themselves scarce. Joe unsheathes his knife, and searches around until he curses about wild boars waking him. As he walks away, he suddenly turns around and throws his knife at a tree in anger, then walks off into the forest.
Tom and Huck go to an old house, and quickly hide in there when they hear Injun Joe and Emmett arrive, searching for the first of Murrell's treasure. Emmett at first thinks the house is haunted, but Joe doesn't believe in superstitions, saying, "Yeah, by rats, maybe". When he reads the map, it says that the treasure is next to the fireplace. The two crooks dig for the treasure, while Tom and Huck, who are in the house attic, use a fishing line to grab the map. But when Emmett asks if the fireplace is the spot where the treasure is buried, Injun Joe walks over to the map, and remind Emmett that they are in the right spot. In the process, as Tom and Huck try to reel up the fishing line, its hook catches his hat. Emmett hits something, and turns to Joe to tell him, but suddenly stares in fear when he sees Joe's hat floating above his hat. Thinking that the house is haunted, Emmett begins screaming. Joe looks up to see his hat floating, but Tom and Huck reel the hat back down, and unhook it. Joe looks up to see what's up in the second story, then looks back to the screaming Emmett, and slaps him back to senses, saying there were no ghosts, but cobwebs.
The two villains pull up a treasure chest, and open it to see gold coins. Emmett is overly excited, but Injun Joe tells him to keep the treasure at Number Two under the cross at the McDougal's Cave, while Joe makes sure that Muff takes the blame for Robinson's murder at the trial. Acquiring all the treasure, Injun Joe burns the map, leaving no evidence to claim Muff innocent.
Injun Joe goes on his mission to find the witness of the murder. He asks one of Tom's friends who owned the marble. The boy tries to remember the former owners of the marble, until Joe, who loses his patience, grabs him by the collar and demands him to tell him who had the marble last. The boy says Tom Sawyer had it last, but doesn't matter since he is dead - the town thinks Tom died in a storm. Injun Joe, in sadistic relief, says that he is sad to hear it, when he is just glad that his one threat is eradicated. But when Tom is revealed to be alive, Injun Joe decides to find him.
Injun Joe runs into Tom Sawyer at Huck's home, picks him up and throws him into the ground. Then, as Tom backs away, Injun Joe corners him at the tree with a picture on it, and gives him back his marble. Tom, knowing of what he will do to him, tries to say that marble isn't his, but Injun Joe tells him not to lie. Then Tom says it is his, but he lost it three months ago. Injun Joe hurls a knife at Tom, but it only hits the tree next to him. Joe tells him to fetch him back the knife. After hesitating, Tom does, and gives it back to the villain. But Injun Joe then goads Tom into stabbing him, and opens his shirt so Tom might have his chance. Tom hesitates, but when he finally begins, Injun Joe moves out of the way, and grabs Tom, threatening him that if he tells anyone that it was Injun Joe who killed Dr. Robinson, he will kill him. He then vanishes.
At the trial of Muff Potter, Injun Joe says in his testimony that he was at the cemetery, and that he liked to sit and look up at the stars. Then, he saw Muff, drunk in a rage, lifting his knife, and stabbed Dr. Robinson four times, until he was dead. All seem to agree on Joe's behalf. But then Tom is called to the stand for Muff's defense. Tom is asked who really killed Robinson, but he hesitates when Injun Joe contemptuously stares at him, reminding him that he will kill him if he reveals Muff's innocence while unsheathing his knife. It is only when Mr. Dobbins says that Tom Sawyer wouldn't know the truth if it kicked him in the teeth, and that he is an outright liar that Tom can't take it anymore. In anger, he reveals Joe's crime, deciding that his friendship with Muff is more important than his oath with Huck. With Muff found innocent of all charges and the town turning on Injun Joe, the villain hurls his knife at Tom, but the boy defends himself by using the Holy Bible as a shield.
Injun Joe flees through the window, and returns to the tavern in anger, where he finds Emmett packing shovels and picks. He realizes Emmett is going to Number Two under the cross to get the treasure for himself. Emmett claims that he wouldn't cheat Joe, while trying to reach for a weapon. Injun Joe agrees and replies that the only reason is that Emmett's smart enough to know that if he ever did, Joe would kill him. And as Emmett reaches for his gun, Joe does so by tossing his knife into Emmett's back, killing him.
During a festival the next day, a group of the children, including Tom and his love interest Becky Thatcher, enter McDougal's Cave. But the two become lost. They stumble upon Injun Joe, who decides to hold up his end of the promise by killing Tom, and who had been looking for Tom within the cave. He traps them, but Tom and Becky manage to escape. After he helps Becky escape, Tom finds the treasure at Number Two under the cross.
Just then, a sand-faced Injun Joe finds Tom, and again tries to kill him. He says he has it all - the treasure and Tom. Before he attempts to kill the boy, Tom hits Injun Joe in the leg with a sword. But Joe, recovering from the slash, punches Tom off, sending his cutlass toppling into a deep chasm. Without a weapon or any defense, Tom is almost stabbed to death, but Huck returns to help save Tom. He kicks Injun Joe, and he nearly slides off into the chasm, with his hat descending down instead. Injun Joe looks at Huck carefully, and recognizes him as "Pap Finn's boy", saying he was the best knife fighter on the Mississippi, then asks if he taught him. Huck says that he did.
Laughing sadistically, Joe challenges Huck to a duel, which Huck badly loses. Injun Joe prepares to kill Huck, when Tom threatens to toss the treasure chest into the chasm. Not wanting to lose his treasure, Joe tries to pry it out of Tom's hands. He suddenly leans backwards over the chasm, with the chest in his arm while grabbing on to Tom's left sleeve and Huck grabbing onto the other. Suddenly, the sleeve Injun Joe grabs onto rips, and the evil man, screaming, falls into the enormous chasm to his death.
Injun Joe is cold-hearted, cruel, remorseless, ruthless, and very dangerous. Like the stereotypical Native American half-breeds, he is deeply antagonistic towards the town citizens. But he is also greedy, willing to kill people for money and/or treasure. He showed his greed in killing Doctor Robinson, who was trying to take the map to Murrell's Lost Treasure. But like all villains, this greed leads to his downfall. When he saw Tom threaten to toss the treasure chest into the cave's chasm, Injun Joe tried to get it back, only to fall to his doom in the end.
Injun Joe is dressed in a ragged shirt with a soot dark blue jacket covering it. On his head is a wide-brimmed dark brown hat.