Medium Pure Titan (5 to 7 Meters)

Damage Reduction. All bludgeoning, piercing, slashing, force, and thunder damage is reduced by 7.

Regeneration. A Titan regains 10 hit points on the beginning of its turn. It heals incapacitated limbs in 2 rounds, regenerates severed limbs in 5 rounds, and regenerates a head in 1 minute. Count the rounds at the beginning of the titan's turn. This feature works as long as the Titan isn't dead. 

Mindless. Titan automatically fails all dexterity, intelligence, and wisdom saving throws.

Siege Monster. Titan deals double damage to structures.

From Thin Air. Titans are not made of regular flesh. They weigh 10 times less than humanoid creatures their size.          

Immortal. When a Titan drops to or below zero hit points, it does not die. Rather it becomes incapacitated, prone and otherwise looks dead. When a Titan regenerates above 40 hit points, it is no longer incapacitated unless the head is severed and hasn't regenerated.

We Reside In The Nape. The Titan may be killed if 10 bludgeoning, slashing, radiant, necrotic, acid, or thunder damage is dealt to its nape before its next turn begins. Creatures may target the nape (Though most won't think to unless they have a degree of knowledge on Titans). The nape has an AC of 18 and can only be hit if the attacker has advantage on an attack roll against the Titan. When a Titan is killed, its body emits steam and decays in 1d4 minutes.

Solar Powered. If Titan is deprived of sunlight for 3 hours, it is incapacitated until it receives 1 minute of sunlight.

Grab. The Titan expends a full round action in an attempt to grapple a target within 10 feet of it. (+5 on athletics check) If it succeeds, the target is moved to the square the Titan is immediately facing and is 15 feet off the ground provided that the target is medium or smaller and within the Titan's lifting capacity (Otherwise the target is grappled normally). The titan's bite attacks have advantage until grapple ends. If the target breaks from the grapple, it falls 15 ft. Grab may be done in place of an opportunity attack.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., 1 target. Hit: 12 (3d4 + 5) piercing damage. This attack may only be done if the target is larger than medium, or is 15 ft. above the ground.

Consume. When the Titan makes a bite attack, it attempts to grapple the target with its jaw as a bonus action. (With advantage if target is already grappled by Titan) If it succeeds,  the target is moved to the square the Titan is immediately facing and is 15 feet off the ground provided that the target is smaller than large and within the Titan's lifting capacity. The Titan gains advantage on rolls to maintain the grapple and may use a full round action to automatically deal its bite damage as a critical hit to the grappled target. If the target dies whilst in this grapple, it is consumed by the Titan. If the target escapes the grapple, it falls 15 ft.