Kingdom Hearts 358/2 Days
After pulling a prank on Roxas, Barrel finds something strange in the Graveyard and decides to keep it at the Manor Ruins. It eventually begins to grow into a Heartless.
After finishing a mission to exterminate a Carrier Ghost at Halloween Town, Roxas heads back to the castle. However, as he approaches the portal home, he is startled when a Tentaclaw suddenly bursts from the ground. He defeats the Tentaclaw and goes home, but a month later, the Organization learns that all the Emblem Heartless have mysteriously disappeared from Halloween Town.
Roxas is sent to investigate, and discovers that Tentaclaws have overrun the town. He tracks them to their source, and finds the Leechgrave, which had been eating the other Heartless. After a battle, Roxas defeats the Leechgrave and releases its heart. Unbeknownst to Roxas, Jack observes him while brainstorming new scares. The combination of Roxas's black coat and the Leechgrave's tentacles inspires Jack to create the Scarecrow, which he presents to Dr. Finkelstein, as Roxas passes by on his way home.
The Leechgrave's main body is a decrepit, black coffin with pale gold lining. The coffin is surrounded by a large, silver chain, has two large, silver nails driven partway into it, and has a small hole near its top where a single, glowing yellow eye peers out. Occasionally, two large, pale green, clawed hands force their way out of the coffin, though no other part of the coffin's contents are visible. Its Heartless emblem, decorated by red patterns resembling claw marks, is located on the lower half of the coffin. The coffin hangs from a pink and red-violet bud with angular, pale yellow spirals for eyes. The bud sprouts four dark green, thorny roots that anchor the Leechgrave to the ground.
The roots are the source of the Tentaclaws, which act as the Leechgrave's appendages. Tentaclaws are black creatures lined by thorns, with red tips and three black mandibles, each with three curved spikes resembling scythe blades.
The Leechgrave's name references the casket-shape of its body and its cannibalistic behavior. By devouring other Heartless, it steals the hearts Organization XIII hopes to use, thus making it a leech or parasite to their goals. Its Japanese name, "Parasite Grave", is similar to another Heartless boss, the Parasite Cage (パラサイトケイジ?). The Tentaclaw's name reflects its tentacle-like body and its clawed mandibles.
Equip Fire magic for this battle.
The Leechgrave is a large Heartless rooted in the ground. At the start of the battle, four Tentaclaws spawn around the Leechgrave.
The safest strategy is to avoid directly attacking the Leechgrave: it is immune to magic, and any melee attack will leave Roxas in range of its high-damage Slash attack. Focus instead on destroying the Tentaclaws using attacks and Fire spells, while dodging the Leechgrave's Pollen Shot and Poison Gas attacks. Block the Tentaclaws' Swallow attack to stun them, leaving them open to attack.
When all four Tentaclaws are destroyed, the Leechgrave falls over and stops attacking. Use this opening to attack the Leechgrave directly. After a brief period, the Leechgrave recovers and all four Tentaclaws regenerate.
Damaging the Leechgrave while its Tentaclaws are alive is dangerous but possible. To do so, approach the Leechgrave, then quickly move out of range before it Slashes. Slash has a short cooldown, leaving a brief opening for Roxas to deal damage. Be ready to move away once the Leechgrave begins another attack.
To increase Roxas's damage output, consider using Limit Break. Kill three Tentaclaws, then leave the fourth to whittle away at Roxas's health. Kill the fourth Tentaclaw when Roxas's HP reaches the Alarm Zone. Then, unleash a Limit Break on the Leechgrave while it is stunned.