Cannoneer's Constructs

Immutable Form. The Cannoneer's Construct is immune to all effects that would change it's form. 

Mechanic Powerhouse. The Construct's brute force can rival that of the strongest athletes. They can dash, disengage, and grapple as a bonus action. Whenever the Construct grapples a target, they can make a slam attack as part of that grapple. They also ignore difficult terrain, and have advantage on strength saving throws. 

Magic Resistance. The Cannoneer's Construct has advantage on saving throws against magical effects. 

Cannon of Fortune. When the cannon makes an abnormal shot, and hits, roll a d100 on the table to determine what occurs:

1-5: For the next 3 turns, any spells that are cast at the construct or any creature within 20 feet of the construct require a DC 16 ability check with the creature's spellcasting modifer. On a fail, the spell is not cast, and is stored inside the construct. The construct's spell storing works the same as a ring of spell storing, and can only store up to 5 levels inside of it. It can release these stored spells all at once as a bonus action, casting them however they would like. All spells have the same save DC and to hit modifier as the caster of the spell/spells. It will automatically release these spells if it becomes full, or if it ends it's third turn since this effect activated without releasing the spells. 
6-8: If the hit target is a creature, it is teleported 30 feet to any location of the cannon's choosing.
9-11: The cannon fires a purple beam of force. If the target is a creature, they must succeed on a DC 16 DEX saving throw or be afflicted with crackling force moving through their body. For the next minute, the creature will take 1d8 force damage on the start of each of their turns. The effect can be ended by a DC 16 CON save, which can be made at the end of the creature's turns. 
12-14: Vines grow out from the cannon and attempt to grab the nearest hostile creature. A creature of the cannon's choosing within 15 feet of the cannon must succeed on a DC 16 STR saving throw or be pushed 15 feet back by the vines, and become grappled and restrained.
15-17: Protective Lights begin to swirl around the cannon and any ally within 10 feet. Until the cannon fires its wild magic cannon again, any creature affected by these lights gain a +1 to AC. 
18-20: Small spectral needles begin to swirl from around the cannon. Until the cannon fires it's wild magic cannon again, any creature that makes a melee attack against it takes 1d8 force damage.
21-23: The cannon overloads, and a 3rd level fireball explodes, centered on the cannon.
24-26: The cannon casts magic missile as a 3rd level spell.
27-29: The cannon heals 3d6 temp HP, and the cannon's shot does 3d6 extra necrotic damage.
30-32: If the cannon hits a creature, that creature must make a DC 16 CON save or be affected by the levitate spell. This effect requires concentration from the cannon.
33-35: The cannon casts chromatic orb at 2nd level. If the cannon shot hits, the orb hits.
36-38: The cannon regains 2d10 hit points.
39-41: Three random creatures within 30 feet of the cannon take 4d10 lightning damage, as bolts of lightning shoot out from the cannon and curl randomly.
42-44: If the cannon hit a creature, have it cast hold monster on the creature, save DC 16.
45-47: The cannon casts mirror image.
48-50: The cannon polymorphs into a random creature in the monster manual. 
51-53: The creature hit by the cannon cannot speak, as pink bubbles shoot out of their mouth instead.
54-56: If the creature has hair or fur, that hair or fur animates, attempting to strangle the creature. If the creature relies on breathing, have the creature make a DC 16 STR save or become grappled and begin to suffocate. They can repeat this save as an action, and also at the end of their turn.
57-59: The cannon grows large bat wings, which give it a flying speed of 30 feet until the end of their next turn. 
61-63: The cannon can take another action.
64-66: The cannon grows in size, becoming a large creature. While large, they do an extra 1d10 damage on attacks, and gain an extra +1 to their attack rolls. 
67-69: If the cannon hits a creature, that creature must make a DC 16 WIS saving throw or fall under the effects of a philter of love.
70-72: If the cannon hit a creature, that creature now has vulnerability to bludgeoning, slashing, and piercing damage.
73-75: One creature within 30 feet of the cannon must make a DC 16 WIS saving throw. On a failed save, the creature takes 4d6 psychic damage and must subtract a d6 on their next saving throw, attack roll, or ability check.
76-78: 5 feet in every direction where the cannon shot landed is affected by the mold earth spell.
79-81: If the target is a creature and they are hit by the cannon, they must make a DC 16 CHA saving throw or be banished into the ethereal plane for 1 minute. This effect does not require concentration.
82-84: If there is an inanimate object that is not being worn or carried, within 60 feet of the cannon, that object will animate, and will follow the cannon's orders. 
85-87: If the target is a creature, that creature must make a DC 16 WIS saving throw or become polymorphed into a bunny. This effect does not require concentration, and can only be dispelled by remove curse, or dispel magic. If the bunny is reduced to 0 hp, the effect ends.
88-90: An arcane shield appears around the cannon. Until the end of the cannon's next turn, the cannon has 50 TEMP hp. 
91-93: A specter summons within 5 feet of the cannon. The specter follows the cannon's orders. If the specter knocks a humanoid below half HP, that humanoid has a specter appear within 5 feet of them. This effect applies to all other specters summoned. 
94-96: Tentacles lash out around where the cannon impacted. Any creature within 10 feet of the location of the cannonfire must make a DC 15 CON save or take 1d12 necrotic damage, the cannon also gains 1d12 temp hp.
97-99: Reverse Gravity is cast where the cannon shot lands. This effect does not require concentration.
100: Roll on the bag of beans table. Whatever effect is rolled occurs within 20 feet of where the cannon shot landed. 

Multiattack. The cannon takes 2 attacks per action, one with it's standard cannon, and one with it's wild magic cannon. Alternatively, they can replace the standard cannon attack with a slam attack. 

Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., 1 target. Hit: (2d10 + 5) bludgeoning damage, and the target must make a DC 15 STR save or be knocked prone.

Standard Light Cannon. Ranged Weapon Attack: +7 to hit, range 250/500 ft., 1 target. Hit:  (4d10) bludgeoning damage.

Wild Magic Cannon. Ranged Weapon Attack: +8 to hit, range 120/300 ft., 1 target. Hit: (4d8) force damage. Roll on the Cannon of Fortune table.