Spider Climb: The spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Regeneration: The symbiote regains 10  Hit Points at the start of its turn. If the symbiote takes thunder or fire damage, this trait doesn't function at the start of the symbiote's next turn. The symbiote dies only if it starts its turn with 0 Hit Points and doesn't Regenerate. 

Web (Recharge 5-6): Ranged Weapon Attack: +7 to hit, range 30/60 ft., one creature. Hit: The target is Restrained by webbing. As an action, the Restrained target can make a DC 15 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed - AC 10; hp 5; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage.

Invisibility: The symbiote magically turns Invisible until it attacks, or until its Concentration ends (as if concentrating on a spell). Any Equipment the symbiote wears or carries is Invisible with it.

Multiattack. The symbiote makes two slam attacks.

Slam. Melee Weapon Attack: +7 to hit, reach 10 ft., 1 target. Hit: 25 (4d12 + 4) bludgeoning damage.