1. Sharks - Spawn mainly in the deep ocean, and can be rarely found near the shore. When killed, they drop 0-2 teeth. Their attack is to charge at nearby players, and biting them. They are very dangerous.
2. Underwater Caves - Caves underwater with lots of kelp, sea grass, and limestone (which isn't planned to be added later)
3. Liquid Magma - Found deep underground. Similar to lava, but much slower and has a texture almost exactly like magma block. Instead of creating obsidian, it can exist inside water.
4. Trenches - Found deep underwater, these trenches have magma blocks and liquid magma. They are less deep than ravines, but are much longer.
5. Sunken Treasure - Found rarely in caves or the seabed. You could get a trident, some gold, or rarely a few diamonds.