Cook-O-Matic

Immutable Form. The Cook-O-Matic is immune to any spell or effect that would alter its form..

Hot Stove, don't touch. Any creature that starts its turn within 5 feet of the Cook-O-Matic takes 4 (1d8) fire damage.

Faulty craftsmanship. Upon a successful hit of 10 or more piercing, bludgeoning, or slashing damage, oil shoots out of the cook-o-matic, filling the 5 foot square next to it in the direction of the attack and making it difficult terrain for 1 minute. Any creature who begins its turn in the square or enters it must make a DC14 Dexterity save or become prone.

Weakness. The off switch. Underneath the machine. A character can use an action to make a Perception check DC20 to find it. To deactivate the machine, they must lie prone and make a successful DC15 Sleight of hand check to switch it off. They risk being run over (2d4 bludgeoning) and take 4 (1d8) fire damage.  

Multiattack. The Stove-O-Matic makes three Knife attacks, or one Knife attack and one Boiling Pot attack at a random creature.

Knife. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: (2d4 + 5) slashing damage.

Boiling Pot Ranged Weapon Attack: +7 to hit, range 90 ft., one target. Hit: 11 (2d6 + 5) bludgeoning damage, and 16 (4d8) fire damage. 

Belch Fire (Recharge 4–6). The stove belches fire in a 15-foot cone. Each creature in the area must make a DC 10 Dexterity saving throw, taking 22 (4d10) fire damage on a failed save, or half as much damage on a successful one.