Wait, I just remembered somthing important. We can't catch angler fish at a lake! Angler fish are saltwater fish, so they only live in water that contains large amounts of salt like an ocean. Only freshwater fish live in lakes because they live in water that doesn't contain salt.
Earlier, I took Mulch's boat into the sea to catch angler fish. I was minding my own business when a giant dragon suddenly appeared! I hopped in my giant bucket and paddled out of there.
I had to leave a barrel of really valuable glowworms on the boat. They're really hard to get, so I can't lose them... Do you think you can find it for me? It should still be in the boat. I took the boat to my secret fishing spot.
The living things that survive in any area is called an ecosystem, and the angler fish has a role to play in their home. They live and thrive in the deep ocean, and that's the only place you can catch them.
2- Discover the fate of Mulch's ship [fly outside the caldera, you are teleported to Explore the sea location]
Bucket told me what happened. Did you find a big beastie out there?
Well these fish aren't going to catch themselves. Since we lost the boat, we'll need to create special tools to catch these fish. You see, their habitat, or the natural environment that an organism lives in, is in really deep waters. We'll need a special rod and a longer line to catch these fish.
I'll create a longer line using fibers from flax flowers. You see, fibers from flax flowers can be threaded into fine, thin rope that is both strong and reliable. Grow some flax flowers in your farm and bring me 6 of them.
Alright! Can you catch 2 angler fish? Remember to use the glowworms as bait. Glowworms have something called bioluminescence - their bodies glow!
In the deep sea ecosystem, the water is very dark because the sunlight can't reach it. The glowworm's light in this dark environment attracts all the fish!
The Gronckle's saddlebags will contain your bait, click on those after you find a good spot over the water to fish from.
Thank you laddie. I didn't know how I was going to do it! You saved my hide.
Known Glitches
Step 8: using a Gronckle will allow you to find a fishing spot, but clicking on the bait bags on your dragon will not show your baits, and you can't fish.
Solutions: A) go to another fishing spot (at School or Berk), click on your bait bag and on a Glowworm, then leave. This will keep the glowworm as bait ready on your fishing rod. Go back to the Open Sea, find the fishing spot again, and now it should directly show the fishing commands.
B) fish the 2 Angler in your farm's fishing spot, using the glowworms.
History
Before an unknown Update (potentially 21st of January, 2020's 3.5.0 with the Titan Hobgobbler Update), players could fish an angler in any type of fishing spot if using a glowworm, without the need to have a gronckle, bypassing the paywall. Currently, anglers can still be catched in your Farm, potentially working as a workaround for step 8.