Mog is a playable character in Final Fantasy VI. He is the only optional character in the World of Balance, and is recruitable with all other party members in the World of Ruin. He also briefly fights alongside the Ten Moogles at the start of the game.
Offensively Mog is a magically-inclined character, with above-average Magic and Speed and poor Strength and Stamina. Mog has some of the best defensive stats of any character other than Umaro, with the highest Magic Defense and second-highest Defense after Sabin. His Evasion and Magic Evasion are also above-average.
Mog can equip spears, daggers, universal shields, hats, and light armor. At the start of the game during the battle to save Terra, Mog is equipped with a Mythril Spear and Mythril Shield, which can be removed from him for other party members to use. When he rejoins later in the World of Balance, he is equipped with a Mythril Spear, Golden Shield, Golden Helm, and Golden Armor.
Along with Gau and Umaro, Mog is one of three characters able to equip the Snow Scarf, the most powerful piece of defensive gear in the game. He has an exclusive relic, Molulu's Charm, which eliminates random encounters.
Mog's equipment draw gives him many options for armor that boosts his Magic, and the Snow Scarf makes him the hardiest mage in the game. With Molulu's Charm Mog is extremely useful throughout the World of Ruin—players can use the charm to avoid battles if the party is weak, to complete dungeons faster, and to explore late-game areas without fear of high-powered enemies. This also makes him invaluable in speedruns and low-level challenges.
Mog's weaponry is unremarkable save for his access to spears. As one of only two characters in the game able to equip spears other than the Impartisan, Mog can use the Dragoon Boots and Dragon Horn to fight as a Dragoon, using Jump attacks that can hit multiple times. With the exception of his ultimate weapon, the Gungnir, spears deal 3x damage when using Jump, letting Mog deal heavy damage. Coupled with his high magical aptitude, Mog can be a potent physical or magical attacker as needed.
Mog's ability is Dance, a mixture of the Animals and Gaia battle commands from Final Fantasy V. There are eight Dances, associated with eight different types of terrain. When Mog completes a battle in one of those areas, he will learn the Dance associated with it. When Mog Dances, there is a 50% chance he will stumble and do nothing, but once completed successfully, the battle background changes to the one associated with the Dance. If the battle background is already a kind associated with the Dance selected, Mog will not stumble.
When Dancing, Mog enters a berserk-like state where he will act automatically each turn until KO'd or petrified. Each Dance has four attacks with the chances of using them divided into a 7/16 chance, a 6/16 chance, a 2/16 chance, and a 1/16 chance. Some Dances share attacks, but the odds of that attack occurring may differ. All of Mog's Dance attacks rely on his magic, and are mostly offensive attacks but include some status and support attacks. They also allow Mog access to earth, wind, and water-elemental attacks, uncommon elements for the party.
Mog's Dance attacks are powerful in the World of Balance and can be very effective when used properly. He can wipe out enemy parties, fully heal the party, or instantly kill enemies with no drawback or MP cost. Their utility declines in the World of Ruin, as late-game magic spells are much stronger than Mog's Dances and his unpredictable nature makes them undesirable to use in difficult battles.
Mog can be recruited after completing the Magitek Research Facility and returning to Narshe. Lone Wolf the Pickpocket is stealing from a treasure house on the east side of town, and if the party finds him and pursues him to the Narshe Cliffs, they will find Lone Wolf holding Mog hostage. After approaching him and then holding still for a period of time, Mog will fight back and he and Lone Wolf will be thrown to opposite sides of the cliff. If the player approaches Lone Wolf, they will take a Gold Hairpin from him, while saving Mog recruits Mog to the party.
In the World of Ruin, Mog appears in the Narshe Mines in the moogles' lair. Speaking to him will prompt him to join the party. This can be done even if Mog was not recruited in the World of Balance, either by skipping him entirely or by not saving him from Lone Wolf. The spot where he is standing in the cave contains Molulu's Charm.
If Mog is not recruited in the World of Balance, his only way of learning the Water Harmony Dance is through the battle with Leviathan, exclusive to the Game Boy Advance and later versions. In the Super NES and PlayStation versions, Mog cannot learn Water Harmony if it is not learned in the World of Balance.
At the start of the game, Mog fights alongside the Ten Moogles in the Battle to Protect Terra. He leads the second party equipped with a Mythril Spear and Mythril Shield. Because Mog joins the party later in the game, he is the only moogle able to have his equipment removed, granting two powerful items early in the game.
Mog is the character the player controls when choosing which of the Three Scenarios to play. This is a different version of Mog that has no ability and cannot have his equipment changed.
Mog must be in the party to recruit Umaro after defeating him in the Yeti's Cave. If Mog is not in the party when Umaro is defeated, Umaro will remain collapsed in his lair until the party returns with Mog.