Siege Monster. The colossus deals double damage to objects and structures.

Howdah. The ogre carries a compact fort on its back. Up to four Small creatures can ride in the fort without squeezing. To make a melee attack against a target within 5 feet of the ogre, they must use spears or weapons with reach. Creatures in the fort have three-quarters cover against attacks and effects from outside it. If the ogre dies, creatures in the fort are placed in unoccupied spaces within 5 feet of the ogre.

Multiattack. The giant makes two greatclub attacks.

Greatclub. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 18 (3d8 + 5) bludgeoning damage.

Rock. Ranged Weapon Attack: +8 to hit, range 60/240 ft., one target. Hit: 21 (3d10 + 5) bludgeoning damage.

Block the Path. Until the start of the ogre’s next turn, attack rolls against the ogre have disadvantage, it has advantage on the attack roll it makes for an opportunity attack, and that attack deals an extra 16 (3d10)bludgeoning damage on a hit. Also, each enemy that tries to move out of the ogre’s reach without teleporting must succeed on a DC 14 Strength saving throw or have its speed reduced to 0 until the start of the ogre’s next turn.