Gargantuan robot, any

Armor Class: 22

Hit Points: 600

Speed: 60 ft , fly: 0 ft , swim: 60 ft

STR

30 +10

DEX

20 +5

CON

30 +10

INT

10 +0

WIS

10 +0

CHA

10 +0

Saving Throws: Advantage on Magical, Strength, Constitution saving throws, 3 Legendary Saves

Skills: Advantage on Strength and Constitution checks, Athletics +17 (A), Acrobatics +17

Damage Resistances: All damage except spells level 7+, very rare weapons, Force and Electrical

Damage Immunities: Damage threshold 15, Poison, Necrotic, Radiant

Condition Immunities: Poisoned, Charmed, Dominated, Confused, Grappled, Restrained, Stunned, Paralyzed, Incapacitated

Senses:

The cockpit instruments offers +17 passive perception, true sight 120ft and there's a searchlight mounted on the bottom of the head.

Challenge Rating: 25 ( 65000 XP)

Proficiency Bonus: 7

Actions

Makes 2 arm weapon attacks, 1 head attack and can make an extra melee attack

• Steam Cannon: Range 300/1200, Fires a steam powered round, 1d20+17 , on hit 2d10+10 bludgeoning damage, STR Save DC25, on failure the creature is knocked prone and pushed 10ft away from the target location.
  • Explosive Shell: Add 2d6+10 Force damage in a 15ft radius, DEX Save DC22 for half damage, make the prone save with disadvantage and adds 10ft to the push.
  • Gas Shell: Add 2d6+10 Acid damage in a 20ft radius, CON Save DC22 for half damage. Stays for 3 rounds or if a Gust of Wind spell is used.
  • Anti-Magic Shell: Dispells all magic effects in a 30ft radius, [Spell casting MOD] Save DC22, autofails when the creature is not a spellcaster. Stays for 1 round and can be ignored with 1 Power Die
  • Electrical Shell: Add 2d6+10 Electrical damage in a 15ft radius, DEX Save DC22 for half damage
• Harpoon Gun: 1d20+17 , on hit 2d12+10 Piercing damage, STR Save DC25 or get dragged to the creature. Any flying creature gets grounded until they make the save.
• Melee attack: 1d20+17 , on hit 2d12+10 Slashing/Bludgeoning damage, STR Save DC25 or get knocked prone

Below Actions can be used once and recharge on a 5 or 6 on a 1d6
• Las Repeater Cannon: in a 60ft cone DEX Save DC22, on failure half damage, 20d6 Radiant damage, takes 1 turn to reload.
• Tesla Coil: in a line 300ft DEX Save DC22, on failure half damage, 20d6 Electrical damage, takes 1 turn to reload.
 

Bonus Actions

• Stomp: All objects topple and all creatures must make a STR Save DC25 or fall prone

Legendary Actions

Has 2 legendary actions:

• Melee attack: 1d20+17 , on hit 2d12+10 Slashing/Bludgeoning damage, STR Save DC25 or get knocked prone
• Shoulder Cannon: 1d20+17 , on hit 2d12+10 Piercing/Bludgeoning damage

Lair Actions

Launch Drone: launches 1d4+1 Attack Drones, Repair Drones and Recon Drones

The Steam Behemoth is so large it counts as it's own lair.

Gargantuan robot, 60ft (18m) tall and 20ft (6m) wide, weighing 100 tons, with exposed clockwork mechanics, hydraulics and exhausts billowing a mixture of black smoke and steam out of its back. It's armored and has huge guns mounted on it's chassis.

 

Uses Intelligence, Wisdom and Charisma score of the pilot. Making targeted attacks on the cockpit are against 30 AC.