Chemical beast

Tight skin - reduces any bludgeoning damage taken by 3

Enraged - Grants +4 to save rolls against control spells

Grappler - Can pick up a small creature and hold it in the hand until taking damage or deciding to throw it up to 20 feet radius as an action.

Chemical rage - as a bonus action may drink a Berserker potion to modify next melee attack with additional 1d6 AoE bludgeoning damage.
Has 2 charges

Raging train - Runs 30 feet forward dealing 2d6+3 damage and pushing everyone from his path for 5 feet.
Stops at the end of his path.

Steroid burst - as an action can use his steroid shot to regain 3d8 +3 hit points.

Fist smash - Melee unarmed attack; +5 to hit; Reach 5 ft; One target; Hit 1d12 +4 bludgeoning damage.

Grapple - Can pick up a small creature and hold it in the hand until taking damage or deciding to throw it up to 20 feet radius as an action.
The creature takes 1d4 +4 damage on holding and additional 1d4 +3 damage upon landing.

Chemical rage - as a bonus action may drink a Berserker potion to modify next melee attack with additional 1d6 AoE bludgeoning damage.
Has 2 charges

Opportunity attack