Legendary Reflexes. The adamant centipede can choose to take 4 reactions per turn.

Tunneler. The adamant centipede can burrow through solid rock at full speed and leaves a 20-foot-diameter tunnel in its wake or collapse it with loose earth and rock if it chooses to.

Magic Resistance. The adamant centipede has advantage on saving throws against spells and other magical effects.

Apocalyptic Monster. The adamant centipede deals double damage to objects and huge or larger creatures. It has +10 to hit when targeting huge or larger creatures.

Destructive Form. Attacks made by the adamant centipede counts as being magical in order to overcome immunities or resistances. In addition, if a creature has immunity to damage made by the adamant centipede, it counts as having resistance instead.

Adamantine Spines If a creature starts within 5 ft. of the adamant centipede it must succeed on a DC 14 Dexterity saving throw or take (2D6) piercing damage and (2d6) slashing damage and be shoved 5ft back.

Multiattack. The adamant centipede can use its Frightful Presence. It then makes six attacks: one with its bite, 5 with its claws.

Frightful Presence. Each creature of the adamant centipede's choice within 120 feet of it and aware of it must succeed on a DC 17 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, with disadvantage if the adamant centipede is within line of sight, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the adamant centipede's Frightful Presence for the next 24 hours.

Bite. Melee Weapon Attack: +8 to hit, reach 20 ft., one target. Hit: 52 (5d12) piercing damage, (3d12) slashing damage and must then succeed on a DC 15 Dexterity saving throw or be knocked prone. When the Adamant Centipede knocks a creature prone with its bite attack it can choose to run it over. The adamant centipede can then move up to 60 ft. The prone target must succeed on a DC 17 Dexterity saving throw or take 68 (6D6) piercing damage, (6d6) slashing damage and (5D12) bludgeoning damage and be shoved half of the adamant centipede's movement.

Claws. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 19 (1d12+3) bludgeoning damage, (1d12+3) slashing.

Twisting body. When the adamant centipede is hit by an attack it can choose to twist out of the way forcing the attacker to reroll the attack.

Fury of claws. When a creature is shoved back by the adamantine spines trait the adamant centipede can immediately attack it with an additional claw attack.

The adamant centipede can take 6 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn or as a bonus action. The adamant centipede regains spent legendary actions at the end of a short rest.

Attack. The adamant centipede makes two claw attacks.

Move. The adamant centipede moves up to 60 ft.

Move Earth. The adamant centipede casts Move Earth twice but the effects are instantaneous.

Control Weather. The adamant centipede casts Control Weather. but the effects are instantaneous.