The King of Thieves
Cassim is a tall man who appears to be in his forties. He looks like an older Aladdin, but has beard, another hairstyle and costume.
Aladdin and the King of Thieves
Cassim left his wife and newborn son in Agrabah eighteen years ago to explore the world and pursue a better life for his family, not wanting to be looked down upon. Some time later, he fell in with the Forty Thieves, eventually becoming their leader (the "King of Thieves"), and incorporated a new law: never hurt the innocent.
Cassim is first seen in the film disguised as the King of Thieves, carrying out a plot to raid Aladdin and Jasmine's wedding. As soon as the ceremony starts, he gives the word for the other thirty-nine to distract the guards while he searches for the Oracle. The plan works, to an extent- Cassim is confronted by Aladdin, and the two fight, both unaware of the fact that they are father and son. He manages to escape, swearing to meet Aladdin again.
Aladdin later catches up to his father after learning he is "trapped in the world of the Forty Thieves", when Cassim utters the secret words to open the hideout of the Thieves ("Open Sesame"). He is confronted by Sa'luk, a rival of his, about the failure of the raid in Agrabah, and Sa'luk is about to kill him when Aladdin intervenes. Aladdin reveals that he is his son, and this is proved when the dagger slips out of his cloak. Cassim tells them that this is true, but nevertheless, since he found the location of their hideout, he must die- or face the challenge in a battle for his life against Sa'luk, which Aladdin narrowly succeeds at.
After the challenge, Cassim shows Aladdin a secret chamber, and Aladdin offers an invitation to his wedding, which Cassim is at first hesitant about, but upon hearing Iago that he will lead Cassim to where the Oracle is if he participates in Aladdin's wedding, he accepts it. Cassim easily bonds with Genie, the Sultan and Jasmine (after a change of clothes and dealing with some of Genie's antics) but is ultimately too obsessed with the pull of the treasure to enjoy the time with his son too much. Nevertheless, as he attempts to take the Oracle, Cassim promises Iago he will go straight to attend the wedding after it, but they are caught by Razoul and the Palace Guards, who have been tipped off by Sa'luk. He is sentenced to life in prison along with 31 thieves that have been captured during Razoul's raid of the hideout, but later on that night, Aladdin, disguised as himself in his King of Thieves clothes, helps him escape.
Once out of Agrabah, Cassim and Iago go back to the Thieves. Upon arriving, they find that Sa'luk manipulated the remaining thieves into believing that Cassim sold them out and now follow Sa'luk as their new leader, despite the fact the imprisoned 31 thieves know that it was Sa'luk who sold them out, not Cassim. Being held hostage with Iago, he is forced to use the Oracle to lead them to the Vanishing Isle, while he secretly commands Iago to escape to warn Aladdin. As the Thieves reached the Isle by ship, Cassim is saved by Aladdin, who knocks Sa'luk unconscious, and they venture into the Vanishing Isle to obtain the hand of Midas. They succeed, but Sa'luk quickly follows, taking Aladdin hostage, threatening Cassim that he will kill Aladdin unless he hand over the Hand of Midas. Cassim, realizing that Sa'luk is a greedy thief, agrees and tosses the hand to Sa'luk who catches it buy the hand instead of the handle, turning him into a golden statue and falls into the chamber filled with water.
Cassim and Aladdin then escape out of the Isle. He throws the Hand of Midas into the sea realizing that he has not lost his ultimate treasure: his son, and apologizes for taking so long to realize it. Cassim attends Aladdin and Jasmine's wedding later, watching from the shadows, as he is still a wanted man for his past crimes. He accepts Iago, who feels he no longer has a place with Aladdin and the others as they prepare for a new life of responsibility, as a travelling companion, and goes off to venture the world. As the film ends, Cassim is last seen with Iago waving farewell to his son and daughter-in-law before riding off to the night.
- Sean Connery was intended to voice Cassim, but he declined.