Uragaan

Rolling.   The Uragaan has a long, agile body, which it can roll into a wheel-shape and use to move around.  While rolling around, the Uragaan gains twice its normal speed.  It loses the ability to make any actions except for its 'rolling slam' action, as well as the ability to stop rolling.

Explosive Rocks.  If the Uragaan begins to roll, it will dispense 1d4 explosive rocks in the locations it started and stopped rolling.  These rocks remain dormant for 1 round, after which they explode.  Creatures within 10 feet of the rocks must succeed on a DC 16 Dexterity saving throw, taking 3d6 fire damage and falling prone on a failed save.

Tar.  The Uragaan's skin consistently secretes a tar-like substance, which is quite sticky.  Any creature who makes a melee attack against the radobaan while it isn't covered in bones must succeed on a DC 15 Strength saving throw, or become grappled by the monster.

Multiattack.  The Uragaan makes two attacks; one with its tail and one with its jaws.

Tail.  Melee Weapon Attack: +5 to hit, reach 5 feet, one target.  Hit: 21 (4d6+7) bludgeoning damage.  

Jaw.  Melee Weapon Attack: +5 to hit, reach 5 feet, one target.  Hit: 23 (3d8+2) bludgeoning damage.  The target must succeed on a DC 15 Dexterity saving throw, or fall prone.

Stomp.  Melee Weapon Attack: +5 to hit, reach 5 feet, one target.  Hit: 20 (4d6+3) bludgeoning damage, and the target falls prone.

Rolling Slam.  If the Uragaan uses its action to roll itself up, it may take a bonus action to attack a hostile creature that it can see.  If it chooses to do so, it must move at least 40 feet in a straight line towards the creature.  The target must succeed on a DC 16 Dexterity saving throw, taking 3d12 bludgeoning damage and becoming grappled to the uragaan on a failed save.

Sleep Gases.  The Uragaan begins to emit a white cloud of gas everywhere within a 10 foot radius of it.  Creatures caught in the smog must succeed on a DC 15 Constitution saving throw, falling unconscious for 5 minutes on a failed save.  They become awakened if they take damage.

Fiery Gases.  The Uragaan begins to emit an orange cloud of gas everywhere within  a 10 foot radius of it.  Creatures caught in the smog must succeed on a DC 16 Constitution saving throw, taking 3d10 fire damage and falling prone on a failed save.

Dispense Rocks.  As a bonus action, the Uragaan can dispense 1d6 more explosive rocks.