Ganondorf, full name Ganondorf Dragmire (according to the A Link to the Past manual), was originally the leader of a band of thieves, according to early Zelda lore. This was later semi-retconned into him being the king of the Gerudos, a race of desert-dwelling thieves. But despite this slight change, Ganondorf’s modus operandi has remained fairly consistent.
Personality-wise, Ganondorf is a megalomaniac. He is single-minded in his quest to conquer Hyrule, and acquire the power he needs to control the land in the process, the mythical Triforce. But with or without the Triforce of Power, Ganondorf is an incredibly skilled swordsman and warlock, and the only people who have ever stand a chance against him are Link and Zelda.
Ironically, even though Ganondorf constantly finds himself in possession of the Triforce of Power, he is no mere brute. If anything, he is one of the most intelligent (and egomaniacal) characters in the franchise. Every interaction with Ganondorf reminds players that he thinks highly of himself and believes everyone else is beneath him. And not only is Ganondorf well-spoken and even sophisticated — at least until his plans are thwarted — but he also often manipulates Link into opening the path to the Triforce without ever actually interacting with him.
If you want to see Ganondorf at his very best/worst, journey inside his castle in Ocarina of Time. As players journey up the final section of his stronghold, Ganondorf plays a pipe organ, which is not only a thematic instrument that instills dread but also one of the hardest instruments to learn and play. And once Link reaches him, Ganondorf claims he is the only one worthy of wielding the Triforce, even though the Triforce itself said otherwise by splitting itself when he touched it.
Most of the time, Ganon is a dastardly anthropomorphic pig, usually wielding a trident. And even when he doesn’t speak, Ganon is capable of casting magic spells, most prominently summoning fireballs and fire bats to take down our little hero. He also sometimes transforms into a thinner monster, such as in Ocarina of Time, or a more bestial pig-like creature, like in Twilight Princess. And that’s not even mentioning his myriad forms in Breath of the Wild. Yet despite these changes, Ganon is still supposed to be an alternate form of Ganondorf — the Hyrule Historia says so. That said, his personality shifts more than the topography of Hyrule.
As previously stated, in the first Legend of Zelda game, Ganon has zero lines or personality; he’s just a gear check to make sure players find the Magic Sword and Silver Arrows, because he can’t be beaten otherwise. In A Link to the Past, he actually receives a few lines and some backstory, but in Ocarina of Time, Ganon is back to being a mute monster…even though he talked when he was Ganondorf. And things get only more confusing from there.