Cannon Colossus (5e Creature)
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Gargantuan construct, neutral or unaligned
Damage Vulnerabilities Acid, Force, Magic Weapons and Adamantium.
Fire Absorption. Whenever the golem is subjected to fire damage, it takes no damage and instead regains a number of hit points equal to the fire damage dealt.
Immutable Form. The golem is immune to any spell or effect that would alter its form.
Magic Resistance. The golem has advantage on saving throws against spells and other magical effects.
Magic Weapons. The golem's weapon attacks are magical.
Siege Monster. Deals double damage to structures and walls
Multiattack. The golem makes two (or four) melee attacks and one Cannon Attacks (or other armaments). The Colossus can be Armed with two Mauls, two Colossus Cannons, two Inferno Mortars or any combination of those weapons. The War Colossus is Simply Armed with two Titan Mauls while the Siege Colossus is Armed with a Colossus Cannon and an Inferno Mortar, finally the Sentinel Colossus is armed with a Titan Maul and one long ranged weapon. (Harpoon Cannon, Shockwave speakers, Lightning Lance)
Titan Mauls. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 30 (4d10 + 10) bludgeoning damage.
Inferno Mortar (Recharge 3-6) Ranged Weapon Attack: Dc.24 range 100/5000 feet, area of effect in 40 by 40 square area (8x8). Hit: 42 (14d6) Fire damage.
Colossus Cannon (Recharge 4-6) +15 to hit, Range 50/5000 Feet, Hit: 60 (20d6) Bludgeoning Damage in a straight line.
Burning oil/Poison Gas (Recharge 5-6). If the Cannon Colossus takes half damage or if the riders inside feel the need for defense they can unleash a storm of Poison yellow gas or great pools of burning oil. in a twenty foot area Around the Cannon Colossus all enemies must roll Dc. 24 Constitution or Dextertiy check or suffer 50 (17d6) Poison or Fire damage.
The 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 regains spent legendary actions at the start of its turn.
Stomp. The Colossus makes a Titan Maul attack but with it's feet. Trample. (Cost 2 actions) The Colossus moves in a straight line 50 feet and everything near it suffers a Titan Maul Attack (Stomping Feet) Reload Ammo! (Costs 3 Actions). The Colossus rerolls on all weapons.
The Ancient Iron War Colossoi that lie buried in the Hordelands and the great deserts, even in the deep forests or oceans of the East. (Search Dc. 20) They are said to be from another age, they are generally completely dormant, there massive Guns and War hammers just gathering dust. If a Character can get inside their Armored Helmets there is a very large crystal sphere supported on a bronze altar, touching this can at least awaken the memory of the Colossus. Spending several hours if not a few days can fully awaken the Colossus in this manner. The Colossus must be operated by mortals inside the Armored Helmet of the Ancient but the inner chambers and can comfortably house several (2d12) medium or small mortals or a few (2d4) large ones. When fully activated a Cannon Colossus can make short work of castles and mountain walls... it can fight an entire Armada and possibly come off victorious.