Multiattack. The megapede makes one Bite attack and uses either Life Drain or Psychic Bomb.
Bite. Melee Weapon Attack: +10 to hit, reach 20 ft., one target. Hit:22 (3d10 + 6) piercing damage plus 22 (5d8) poison damage.
Life Drain. The megapede magically drains life energy from other creatures nearby. Each creature within 15 feet of the megapede must make a DC 15 Constitution saving throw, taking 16 (3d10) necrotic damage on a failed save, or half as much damage on a successful one.
Psychic Bomb. The megapede targets one creature it can see within 60 feet of itself. The target must make a DC 15 Wisdom saving throw. On a failed save, the target takes 22 (5d8) psychic damage and is incapacitated until the end of its next turn. On a successful save, the target takes half as much damage and isn't incapacitated.
Megapedes are enormous centipedes that can be as much as 150 feet long, though most specimens top out at between 100 and 120 feet. Their dozens of legs are each 5 feet long and tipped with flexible claws, and they have fur-covered carapaces. A megapede that lives in a sandy environment often buries itself in the sand and waits for prey to wander nearby, but megapedes also nest in cavernous underground chambers.