Titanium is an important resource in Monster Harvest as you will need it to craft key structures. To get titanium, you must enter the dungeon. You can get it by defeating the Chompy that guards the entrance to the second level of the dungeon.
Once you defeat it, you can open the chest level one chest which rewards the player with a few titanium. The way to the second level of the dungeon will also be clear and that is where you can start collecting titanium in bulk. Later-level dungeon chests will also award titanium.
Related: How to Craft Slimes in Monster Harvest
You can find titanium ore starting at the second level of the dungeon. You can spot it by its orange base color and silver ore fragments sticking out. With the standard pickaxe, it will take three swings to mine the ore. Breaking a titanium ore will give the player one piece of titanium.
You will need titanium to craft items unlocked as you play. For instance, it can craft pipes that allow you to automate your watering and thus save you valuable stamina and time. As you will need a lot of titanium, delve deeper into the dungeon to earn more of this valuable resource.
For more information on Monster Harvest, check out Is there a map in Monster Harvest and How to Refill Your Watering Can in Monster Harvest on Pro Game Guides.