Tannin

"So God created the mighty Tannin, and every kind of creature with which the waters swarm,"
Genesis 1:21

Sea Serpents of Old. On the fifth day of creation, God brought forth creatures of the water and the sky, including a sea monster of mythic proportions. No one is sure how many Tannin there are, how long they live, or if they even die at all. Some legends speculate that the Tannin are the offspring of the Leviathan, while other stories suggest that these massive serpents were once regular snakes that have continued to grow larger and larger since the day of creation. What is known for certain, however, is that the Tannin are to be avoided at all costs. When a Tannin attacks, nothing survives. Because such attacks usually happen on the open water, many trade routes by sea take longer journeys than necessary in order to stick close to the shore or other known shallows.

Did You Know? The Hebrew monster called the tannin is nearly identical to the Hebrew word tannim, which means "jackals." Due to the similarities in these words, there has been a long history of confusion and debate among translators about which word belongs where. For example, the original Hebrew text of Lamentations 4:3 depicts a Tannin nursing its young with its breasts. This verse is likely meant to refer to jackals (since sea serpents do not have breasts), and almost certainly exists as a spelling error from ancient scribes who made a mistake when copying from the original version of the Hebrew text.

Gargantuan monstrosity, unaligned

Armor Class 18

Hit Points 205

Speed Swim 90 ft.

STR	DEX	CON	INT	WIS	CHA
28 (+9)	14 (+2)	26 (+8)	6 (-2)	18 (+4)	10 (+0)

Saving Throws Str +13, Con +12

Skills Athletics +13

Condition Immunity Prone

Senses Darkvision 120 ft., Passive Perception 14

Challenge 12 (8,400 XP)

Features

Amphibious. The Tannin can breathe air and water.

Depth Immunity. The Tannin is immune to all negative effects, including damage, caused by the crushing depths of the ocean.

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

Actions

Multiattack. The Tannin makes two attacks: one with its Bite and one with its Tail.

Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 28 (4d8 + 9) piercing damage and the target is grappled (escape DC 20).

Tail. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 32 (5d8 + 9) bludgeoning damage.

Undertow. The Tannin dives below the surface of the water, creating a devastating rip current in its wake. The Tannin moves at least 30 feet straight down into the water, causing each target (including ships and objects) within 20 feet of the point it left to make a DC 18 Strength saving throw. A target takes 30 (10d10) bludgeoning damage and is pulled 10 feet under the water on a failed save. On a successful save, a target takes half as much damage and is not pulled.

Steam Breath (Recharge 5-6). The Tannin exhales a cloud of scalding steam in a 60-foot-cone. Each target in this cone must make a DC 18 Dexterity saving throw, taking 55 (10d10) Fire damage on a failed save, or half as much on a successful one.

Bible5e custom monster. Its specific traits supplement the current rules. See Using Bible5e Monsters.