Blue Dragons of Fourth Wing

Here’s the stat block for the Blue Dragon from Fourth Wing. I’ll be back with the rest of the tail variations shortly:

Adult Blue Daggertail Dragon (Fourth Wing)

Huge Dragon, chaotic neutral
Armor Class 21 (natural armor)
Hit Points 256 (19d12 + 133)
Speed 40 ft., climb 40 ft., fly 80 ft.

Saving Throws Dex +8, Con +13, Wis +9, Cha +8
Skills Acrobatics +8, Intimidation +8, Perception +15
Damage Resistances fire
Senses darkvision 120 ft., passive Perception 25
Languages understands Common but doesn’t speak, telepathy 500 ft.
Challenge 17 (18,000 XP)

A Pile of Ash. A creature reduced to 0 hit points by the dragon’s Fire Breath is reduced to ash.
Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.

Actions

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite, one with its tail and one with its claws.
Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 7) piercing damage plus 7 (2d6) fire damage.
Claw. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 15 (2d6 + 7) slashing damage.
Tail. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 21 (4d6 + 7) bludgeoning damage.
Frightful Presence. Each creature of the dragon’s choice that is within 120 ft. of the dragon and aware of it must succeed on a DC 19 Wisdom saving throw or become frightened for 1 minute. While it is frightened in this way, a creature must spend its turns trying to move as far away from you as it can, and it can’t willingly move to a space within 30 feet of the dragon. For its action, it can use only the Dash action or try to escape from an effect that prevent it from moving. If it has nowhere it can move, the creature can use the Dodge action. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the dragon’s Frightful Presence for the next 24 hours.
Fire Breath (Recharge 5-6). The dragon exhales fire in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 63 (18d6) fire damage on a failed save, or half as much damage on a successful one.

Reactions

Never Approach a Blue. Other creatures provoke an opportunity attack from the dragon when they enter the reach of its tail.

Legendary Actions

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 dragon makes a Wisdom (Perception) check.
Tail Attack. The dragon makes a tail attack.
Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 10 ft. of the dragon must succeed on a DC 22 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.

I’ll included all variations of the stat block as images.  For now, you can sub out the various tails:

• Morningstartail – 1d10 Bludgeoning, 1d12 Bludgeoning and Piercing, Seige Monster
• Clubtail – 2d10 Bludgeoning, Siege Monster
• Swordtail – 2d12 Slashing reach additional 5 ft. reach
• Scorpiontail – 1d12 Piecing 1d6 Poison, DC 15 CON save for poisoned condition.