Wall Titan

Skinless bodies sheathed in raw muscle give the Wall Titans an unmistakable resemblance to the Colossus Titan of the Nine, though that Titan shows more exposed bone around its face than most of them do. The build repeats across the horde: elongated arms and thick, elephantine feet suited to carrying their enormous frames.

Faces are where individuals diverge. Some are little more than bared skulls, while others carry complete musculature. No exact height is recorded and it presumably varies, but they roughly match the 50 meter Walls that contained them.

Heat is their signature weapon. Like the Colossus Titan they vent scalding steam in huge plumes, useful as a smokescreen or as a killing tool; during the ocean crossing they flash-boil the sea around an entire naval fleet, cooking the crews inside their battleships. Each one can also harden, an ability almost certainly imposed on them through the Founding Titan's commands. That crystallization molded the Walls' outer surface while the Titans inside served as load-bearing pillars, and it ceases entirely once they are freed.

For their size they are shockingly fast. Hange Zoë's estimate of 600 kilometers covered in half a day works out to roughly 50 kilometers per hour, beyond a horse at full gallop, and they hold that pace even while swimming, crossing from Paradis to the mainland within days. Combined with numbers beyond counting and footfalls that level buildings and pulverize anyone underneath, that mobility made the horde the core of Paradis Island's deterrent, the threat known as the Rumbling.

In 743, having engineered the end of the Great Titan War, King Karl Fritz withdraws to Paradis Island with the main Fritz line and part of the Eldian people. There he spends the Founding Titan's power to transform tens of millions of his subjects into giants, arranging them into three concentric Walls sheltering the island's remaining Eldians. His message to Marley is blunt: leave Paradis untouched, or the sleeping horde will flatten the earth. Cut off from sunlight inside the Walls, they stand motionless for over a century.

Their existence first comes to light in Stohess, when Annie Leonhart's attempt to scale a Wall while fleeing Eren tears away a section and exposes a massive face staring out from within. Minister Nick demands the hole be covered before sunlight can rouse the giant, yet refuses to explain anything, even when Hange Zoë nearly throws him off the Wall. The fuller story surfaces later through Grisha Yeager's basement records, which preserve Dina Fritz's account of the Walls' creation, and through Willy Tybur's festival address, which admits the First King's threat was always hollow: his vow of pacifism barred the Founder from war. That safeguard died with the island's coup, and with the Founding Titan in the hands of Eren Yeager, a man bound by no vow, the danger becomes real for the first time.

Eren proves it by freeing Ymir Fritz and setting the Rumbling in motion. The Walls fall apart, and the horde marches for the sea under his command, wrecking towns across Paradis on its way out. The Titans shrug off the Global Alliance's naval blockade, boiling its fleet from below, then walk through coastal artillery fire and grind city after city underfoot, including the port of Odiha, where Hange Zoë dies against the furnace heat of their bodies while buying time. Airships from Fort Salta drop bombs from too high to aim and accomplish nothing before a phantom of the Beast Titan swats them out of the sky. Only Zeke Yeager's beheading by Levi Ackerman halts the march, leaving the giants slumped where they stand. When Mikasa Ackerman kills Eren and the Titan power itself vanishes, the Wall Titans revert to ordinary people, and the survivors of the Rumbling lynch them.