Ancient Hydra

Amphibious. The Ancient Hydra can breathe air and water.

Multiple Heads. The hydra has five heads. While it has more than one head, the hydra has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

Whenever the hydra takes 25 or more damage in a single turn, one of its heads dies. If all its heads die, the hydra dies.

At the end of its turn, it grows two heads for each of its heads that died since its last turn. The Ancient Hydra regains 20 hit points for each head regrown in this way.

Roll a d10 to see what Ancient Dragon Head is created, Results Shown.

1 - Gold Ancient Dragon Head

2 - Bronze Ancient Dragon Head

3 - White Ancient Dragon Head

4 - Copper Ancient Dragon Head

5 - Green Ancient Dragon Head

6 - Brass Ancient Dragon Head

7 - Red Ancient Dragon Head

8 - Black Ancient Dragon Head

9 - Silver Ancient Dragon Head

10 - Blue Ancient Dragon Head

The Ancient Dragon Heads are immune to the Damage that their Breath Weapon does.

Reactive Heads. For each head the hydra has, it gets an extra reaction that can be used only for opportunity attacks.

Wakeful. While the hydra sleeps, at least one of its heads is awake.

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

Multiattack. The Ancient Hydra makes two Bite attacks as it has heads or the Head uses its breath weapon.

Bite. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10+10) piercing damage.

Breath Weapons (Recharge 5–6). The Ancient Hydra head uses the following breath weapon

(Gold) Fire Breath. The dragon exhales fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 71 (13d10) fire damage on a failed save, or half as much damage on a successful one.

(Bronze) Lightning Breath. The dragon exhales lightning in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 23 Dexterity saving throw, taking 88 (16d10) lightning damage on a failed save, or half as much damage on a successful one.

(White) Cold Breath. The dragon exhales an icy blast in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 72 (16d8) cold damage on a failed save, or half as much damage on a successful one.

(Copper) Acid Breath. The dragon exhales acid in an 90-foot line that is 10 feet wide. Each creature in that line must make a DC 22 Dexterity saving throw, taking 63 (14d8) acid damage on a failed save, or half as much damage on a successful one.

(Green) Poison Breath. The dragon exhales poisonous gas in a 90-­-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 77 (22d6) poison damage on a failed save, or half as much damage on a successful one.

(Brass) Fire Breath. The dragon exhales fire in an 90-foot line that is 10 feet wide. Each creature in that line must make a DC 21 Dexterity saving throw, taking 56 (16d6) fire damage on a failed save, or half as much damage on a successful one.

(Red) Fire Breath. The dragon exhales fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 91 (26d6) fire damage on a failed save, or half as much damage on a successful one.

(Black) Acid Breath. The dragon exhales acid in a 90-foot line that is 10 feet wide. Each creature in that line must make a DC 22 Dexterity saving throw, taking 67 (15d8) acid damage on a failed save, or half as much damage on a successful one.

(Silver) Cold Breath. The dragon exhales an icy blast in a 90-foot cone. Each creature in that area must make a DC 24 Constitution saving throw, taking 67 (15d8) cold damage on a failed save, or half as much damage on a successful one.

(Blue) Lightning Breath. The dragon exhales lightning in a 120-­-foot line that is 10 feet wide. Each creature in that line must make a DC 23 Dexterity saving throw, taking 88 (16d10) lightning damage on a failed save, or half as much damage on a successful one.

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The dragon regains spent legendary actions at the start of its turn.

Detect. The Ancient Hydra makes a Wisdom (Perception) check.

Furry. The Ancient Hydra makes as many Bite attacks as it does heads.

Head Growth (Costs 2 Actions). The Ancient Hydra grows another head.