The Lorekeeper's Tome

The Reef Horror is a greater terror of the coastal deeps than any mere crawler: a vast, many-tentacled monstrosity that anchors itself among the deep reefs and lashes out at anything that passes within the long reach of its arms - including the decks of ships that stray too near the rocks. A single Reef Horror can sweep half a crew overboard in a flurry of striking tentacles, and worse, the reefs it favours are exactly the close, dangerous waters where a ship can least afford to lose its hands. Coastal charts mark the worst of their haunts, and wise captains give those marks a wide and respectful berth.