The Elder Mouse is a breed of mouse found in the Tribal Isles region. They are known to drop the Ancient Spear in Cape Clawed. You need to use Shell Cheese in order to catch the Elder Mouse as no other Cheese will attract this mouse to your trap. It is not easy to catch this mouse with Net Cannon but you will still be successful. You need to at least craft 15 to 45 Shell Cheese to catch this Elder Mouse with the Loot depending on your luck.
I have used Net Cannon with Polar Base and using Shell Cheese as my bait to catch the Elder Mouse.
