Coral Corpse

Arcane Conduit. You can cast spells as though you were in the experiment’s space, but you must use your own senses. Once per turn, when you cast an Artificer spell from the Evocation or Necromancy schools and deal damage while your experiment is within 120 feet of you, you can add your Intelligence modifier to one damage roll of that spell.

Boiling Body. The corpse gives off a startling amount of heat so much so that the water surrounding it boils. Creatures who enter withing 5 ft. of the corpse must succeed on a DC (your spells save DC) Constitution saving throw to take 24 (7d6) points of fire damge on a failed save, taking half damage on a success. A creature who starts their turn their must make the save as well.

Desiccation. For each hour outside of water, the corpse suffers 1 level of exhaustion. At 3 levels of exhaustion, its loses Boiling Body trait. At 5 it loses its Flame Tolerance trait. At 7 levels of exhaustion its coral body crumbles to ash leaving only the Coral Catalyst behind.

Flame Tolerance. The corpse is immune to fire damage unless the amount of damage exceeds its threshold. The threshold for its fire immunity is your (artificer level multipled by your Intelligence modifier). If the total fire damage exceeds its threshold then its fire immunity its treated like fire resistance.

Infusable Experiment. Instead of infusing an item at the end of a long rest, you can imbue the experiment with an infusion that targets either its weapon or a part of its armor.

Magic Resistance. The corpse has advantage on saving throws against spells and other magical effects.

Magic Weapons. The corpse's weapon attacks are magical.

Undead Nature. The experiment doesn't require air, food, drink or sleep, and it is immune to disease.

Slam. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage plus 4 (1d8) fire damage. On a natural 20, molten coral fragments embed in the target, dealing 2 (1d4) fire damage on the creature’s turn until removed (action required).