Bellborne Geochelone

Amphibious. The geochelone can breathe both air and water.

Shelled Fortitude. Whenever a creature deals 20 damage or less to the geochelone, the geochelone takes no damage instead.

Multiattack. The geochelone makes one Snap attack and two Stomp attacks.

Snap. Melee Attack Roll: +11, reach 15 ft. Hit: 19 (2d12 + 6) Piercing damage, and the target is Grappled. The geochelone can grapple one creature at a time.

Stomp. Dexterity Saving Throw: DC 19, each creature in a 10-ft. Emanation. Failure: 15 (2d8 + 6) Thunder damage.

Dust Storm (Recharge 5-6). Constitution Saving Throw: DC 16, each creature in a 15-ft. Emanation. 42 (12d6) Bludgeoning damage, and the target is moved 20 feet clockwise from where it started. Success: Half damage.

Swallow. Strength Saving Throw: DC 19, one creature the geochelone has Grappled (it can have 3 creatures swallowed at a time). Failure: The target is swallowed, and the Grappled ends. While swallowed, the creature is Blinded and Restrained, can't teleport, has total cover against attacks and other effects outside the geochelone, and it takes 14 (4d6) Acid damage at the start of each of the geochelone’s turns.

If the geochelone takes 30 damage or more on a single turn from a creature inside it, the geochelone must succeed on a DC 15 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall Prone in a space within 10 feet of the geochelone. If the geochelone dies, a swallowed creature is no longer Restrained and can escape from the corpse by using 30 feet of movement, exiting Prone.

Earthquake (1/Day). The geochelone casts Earthquake without spell components, using Constitution as the spellcasting ability (spell save DC 16).

Legendary Action Uses: 3. Immediately after another creature’s turn, the geochelone can expend a use to take one of the following actions. The geochelone regains all expended uses at the start of each of its turns.

Scream. Constitution Saving Throw: DC 16, each creature in a 200-ft. Cone. Failure: The target is Deafened until the end of the geochelone's next turn and falls Prone.

Crush. Dexterity Saving Throw: DC 19, each creature in a 5-ft. Emanation. Failure: 13 3d8) Bludgeoning damage, and the target is Restrained by debris until the start of the geochelone's next turn (escape DC 19). Success: Half damage, and the target is pushed 5 feet back. The geochelone must use half of its movement to stand back up, and can’t take this action again until the start of its next turn.