There are certainly a few oddities in Skull and Bones. One, in particular, might surprise you, since it's a terrifying creature from the depths. Here's our guide on how to get the Monstrous Tooth from the Sea Monster in Skull and Bones.
How to defeat the Sea Monster to get Monstrous Tooth in Skull and Bones
You can defeat the Kuharibu Sea Monster by dealing as much damage as you can, while also bracing when it's about to ram your ship. Here's a quick summary:
The Skull and Bones Sea Monster is part of a quest called From the Deeps.
You can get this quest from the Sea People Huntmaster NPC in the outpost of Lanitra, which is north of the Sainte-Anne pirate haven.
From there, keep going northwest to the Western Basin. Make sure you disembark at the outpost of Ile Michel, which can act as a fast travel point/respawn point.
The Kuharibu Sea Monster encounter
If you really want to get Monstrous Tooth in Skull and Bones, then you have to sail just north of Ile Michel to find the Kuharibu. It's a bit hard to spot since it's underwater, but you might see it attacking other ships in the area.