This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Aladdin and the King of Thieves
Saluk's death. He grabs the Hand of Midas... literally. This turns him into solid gold with a hellish, muffled scream, causing him to drop into the water.
The Oracle is also a bit creepy.
The Aladdin vs. Sa'Luk fight is pretty intense. At one point Sa'luk slashes Al's arm with his wolverine claws (we only see Al yelling in agony and Abu, Iago and Cassim watching in horror.)
Early previews show Aladdin's sleeve stained with blood during the 40 thieves song immediately afterwards, obviously from that same slash. That got edited out by the time the movie actually came out.
Saluk's character in general is quite off-putting, particularly when he survives his Disney Villain Death and kills a shark onscreen. It's not made clear precisely how he did it, but it was still trying to breathe after he beached it, then it just gives up and dies. Proves that while he may not have any magical powers like Jafar, Sa'Luk is still without a doubt, a terrifying threat! (Especially his knuckleduster that can rip his foes to shreds).
There's also the implication that the Hand of Mindas is King Midas' actual hand, which he cut off when the Be Careful What You Wish For aspect of his "gift" kicked in.