Armor Class 17
Hit Points 152 (16d10 + 64)
Speed 40 ft., fly 80 ft., burrow 30 ft.
Saving Throws DEX +4, CON +7
Skills Insight +5, Perception +5, Stealth +4
Damage Resistances necrotic
Senses Blindsight 30 ft., Darkvision 120 ft., passive Perception 15
Languages Common, Draconic; telepathy 120 ft.
Challenge 8
Multiattack. The dragon makes three Rend attacks. It can replace one attack with a use of Time-Warping Breath.
Rend. m +7, reach 10 ft. Hit: 14 (3d6 + 4) Slashing damage plus 7 (2d6) Necrotic damage.
Ruinous Breath (Recharge 5–6). con DC 15, each creature in a 30-foot Cone. 36 (8d8) Necrotic damage. Half damage.
Time-Warping Breath. wis DC 15, each creature that isn't currently affected by this breath in a 30-foot Cone. The target's Speed is halved, it can't take Reactions, and it can take either an action or a Bonus Action on its turn, not both. It repeats the save at the end of each of its turns, ending the effect on itself on a success. After 1 minute, it succeeds automatically.
FRAiF, p. 277