Sources
CR
Type
Size
Alignment
Movement

Phoenix

Gargantuan Elemental, Neutral

Armor Class 18
Hit Points 175 (10d20 + 70)
Speed 20 ft., fly 120 ft.
STR
19
+4
DEX
26
+8
CON
25
+7
INT
2
-4
WIS
21
+5
CHA
18
+4
Saving Throws WIS +10, CHA +9
Damage Resistances bludgeoning, piercing, slashing, from nonmagical attacks
Damage Immunities fire, poison
Condition Immunities Exhaustion, Grappled, Paralyzed, Petrified, Poisoned, Prone, Restrained, Stunned
Senses darkvision 60 ft., passive Perception 15
Languages
Challenge 16 (15,000 XP)

Traits

Fiery Death and Rebirth. If the phoenix dies, it explodes. Each creature in 60-foot-radius sphere centered on the phoenix must make a DC 20 Dexterity saving throw, taking 22 (4d10) fire damage on a failed save, or half as much damage on a successful one. The fire ignites flammable objects in the area that aren't being worn or carried.

The explosion destroys the phoenix's body and leaves behind an egg-shaped cinder, which weighs 5 pounds. The cinder deals 21 (6d6) fire damage to any creature that touches it, though no more than once per round. The cinder is immune to all damage, and after 1d6 days, it hatches a new phoenix.

Fire Form. The phoenix can move through a space as narrow as 1 inch wide without squeezing.

Any creature that touches the phoenix or hits it with a melee attack while within 5 feet of it takes 5 (1d10) fire damage. In addition, the phoenix can enter a hostile creature's space and stop there. The first time it enters a creature's space on a turn, that creature takes 5 (1d10) fire damage.

With a touch, the phoenix can also ignite flammable objects that aren't worn or carried (no action required).

Flyby. The phoenix doesn't provoke opportunity attacks when it flies out of an enemy's reach.

Illumination. The phoenix sheds bright light in a 60-foot radius and dim light for an additional 30 feet.

Legendary Resistance (3/Day). If the phoenix fails a saving throw, it can choose to succeed instead.

Siege Monster. The phoenix deals double damage to objects and structures.

Actions

Multiattack. The phoenix makes two attacks: one Beak attack and one Fiery Talons attack.

Beak. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit:15 (2d6 + 8) fire damage.

Fiery Talons. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit:17 (2d8 + 8) fire damage.

Legendary Actions

Move. The phoenix moves up to its speed.

Peck. The phoenix makes one beak attack.

Swoop (Costs 2 Actions). The phoenix moves up to its speed and makes one Fiery Talons attack.

Lore

To rise like a phoenix from the ashes–so many use that quaint colloquialism. Little do they know about the true horror of such a rebirth.