Geldarm (5e Creature)
From D&D Wiki
Large beast, unaligned
Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 6 (2d4 + 1) piercing damage.
From beneath desert dunes, a segmented centipede abruptly towers straight up, reaching over a dozen feet into the air to snatch a bird of prey right out of the sky. This is the primary means by which a geldarm hunts. More than a few travelers have fallen to these sudden strikes. Geldarms are most commonly found burrowing just beneath the surface of desert sands, but can also be found on beaches, dry hills, or other terrain of loose dirt and open skies.
Fragile Titan. A geldarm's entire, extremely long and narrow body is almost entirely covered by a plate-like carapace that protects it from most forms of harm. These plates, combined with the geldarm's burrowing evasiveness, enable it to strike hard against prey and survive the strikes of predators. Despite its immense size and aggressive nature, a geldarm is surprisingly fragile to a fighter that knows how to exploit its weaknesses. A well-placed strike finds the insect's skull or spine to break in a single blow, slaying it instantly.