Lifeberg (5e Creature)
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Gargantuan construct, unaligned
Saving Throws Strength +11
Charge. If the lifeberg moves at least 20 feet straight toward a target and then hits it with a ram attack on the same turn, the target takes an extra 16 (2d8 + 7) bludgeoning damage plus 4 (1d8) bludgeoning damage for each size category the lifeberg is above Tiny.
Freezing Body. A creature which touches the lifeberg makes a DC 14 Constitution saving throw, taking 7 (1d6 + 4) cold damage on a failed save, or half as much on a success.
Ice Regeneration. The lifeberg regains 10 hit points at the start of its turn as long as it is in a body of water as large or larger than itself. If the lifeberg takes fire damage, this trait doesn't function at the start of the lifeberg's next turn. The lifeberg dies only if it starts its turn with 0 hit points and doesn't regenerate.
Ram. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 40 (8d6 + 12) bludgeoning damage.
For all intents and purposes an iceberg, albeit one imbued with life and hatred, a lifeberg begins as a shard of obsidian-like black glass which freezes layer upon layer of ice to form its full body. They attack indiscriminately, killing crew, stealing cargo, and eating ships, but do so purely out of malice. With no vital organs or even proper tissues, a lifeberg is hard to slow down and extremely difficult to kill, as only the destruction of its core will stop it for good.