Sources
CR
Type
Size
Alignment
Movement

Reduced-Threat Dragon Turtle

Gargantuan Dragon, Neutral

Armor Class 20 (natural armor)
Hit Points 341 (22d20 + 110)
Speed 20 ft., swim 40 ft.
STR
25
+7
DEX
10
+0
CON
20
+5
INT
10
+0
WIS
12
+1
CHA
12
+1
Saving Throws DEX +6, CON +11, WIS +7
Damage Resistances fire
Senses darkvision 120 ft., passive Perception 11
Languages Aquan, Draconic
Challenge 17 (18,000 XP)

Traits

Reduced Threat. A reduced-threat monster takes a −2 penalty on attack rolls (included in the stat block), ability checks (included in the stat block for skill proficiencies), saving throws (included in the stat block for saving throw proficiencies), and saving throw DCs (included in the stat block).

Amphibious. The dragon turtle can breathe air and water.

Actions

Multiattack. The dragon turtle makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit:26 (3d12 + 7) piercing damage.

Claw. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit:16 (2d8 + 7) slashing damage.

Steam Breath (Recharge 5–6). The dragon turtle exhales scalding steam in a 60-foot cone. Each creature in that area must make a DC 18 Constitution saving throw, taking 52 (15d6) fire damage on a failed save, or half as much damage on a successful one. Being underwater doesn't grant resistance against this damage.