Conjure Cactoid Leviathan

Mustering up all of the power from the cacti around you, you are able to conjure the most powerful cactoid in existence. The Cactoid Leviathan.

At a monstrous 23 feet tall and weighing almost one ton, the Cactoid Leviathan is the most powerful cactus summon imaginable. The Cactoid Leviathan also has significantly different traits than his smaller brothers:

• The Cactoid Leviathan can make melee attacks at a 10ft range that have a hit DC modifier of the caster's unarmed hit DC modifier +9. Melee attacks made by the cactus leviathan deal 4d6 bludgeoning damage, as well as 7d4 piercing damage, as well as the caster's unarmed damage and modifier x3 in piercing damage. Successful hits with the cactus leviathan's unarmed attacks will also stagger the enemy and force them to move 5ft in the opposite direction unless they have a strength stat that is 17 or higher.
• The Cactoid Leviathan cannot hurl needles but can instead spend an action to shoot all of its needles at once in a 30ft spherical radius, that forces all creatures within the radius to make a DEX saving throw. The saving throw must be an 18 or higher, or else any creatures inside the radius will take 10d4 piercing damage as well as be temporarily slowed (-10 movement speed for 1 turn). If an enemy succeeds the saving throw, they only take half the damage and will not be slowed. 
• After the Cactoid Leviathan has shot out all of its needles, it can then spend an action to regain its needles. However, in doing so the Cactoid Leviathan can ONLY use its action to regain its needles and cannot move, use a bonus action, or use a reaction on that turn.
• The Cactoid Leviathan's movement speed is -5ft of the casters.
• Melee attacks made within 5ft against the Cactoid Leviathan will force the attacker to make a DEX and a CON saving throw. Both must be over 16 to succeed, and both must succeed in order for the attacker to not take damage. If the attacker fails on at least one of the saving throws, they will suffer 4d4 piercing damage, will take 1d4 poison damage, and be poisoned for 1 turn.
• The Cactoid Leviathan is immune to being poisoned and grappled, and any creature that attempts to grapple the Leviathan will suffer 4d4 piercing damage, 2d4 poison damage, and will be poisoned for 2 turns.
• The Cactoid Leviathan's saving throws are the same as it's caster's saving throws, however it does get a bonus +2 to its CON saving throw.
• The Cactoid Leviathan's HP is twice that of its caster's HP.
• The Cactoid Leviathan also has attack of opportunity.
• Lastly, The Cactoid Leviathan has a special ability when paired with the 9th spell level of 'Conjure Cactoid'. If the Cactus Leviathan is summoned, the caster can also summon the 9th spell level of Conjure Cactoid at the same time. In doing so, the 9 conjured cactoids will combine with the Cactoid Leviathan, restoring all of the Cactoid Leviathan's HP, and increasing the Leviathan's HP by 200. Additionally, this will also increase the damage output of the Cactoid Leviathan by adding an additional 7d4 piercing damage to every one of its attacks.