The Obsidian Trench is the newest layer buried under Mariana’s Veil, and its bestiary page is small but front-loaded with gatekeeping. Ten of its twelve entries are ordinary catches you can grind out with any decent rod. The last two are the reason most players stall, because one of them is a boss you have to summon yourself.
Quick answer: Catch the ten standard trench species, then the exotic Veiled Charybdis, then the apex Skolopendra. The page flips to 100% and rewards the Obsidian Chunk Bobber.
Every entry on the Obsidian Trench bestiary page
The trench holds 12 species. Ten are named and appear as normal silhouettes on the page. The remaining two are the special encounters the layer is built around, and they only show up once you actually hook them.
- Obsidian Gaveltooth
- Cinder-Crust Gar
- Scoria Scorpionfish
- Shatter-Tooth Shark
- Magma-Glass Marlin
- Tectonic Toadfish
- Ash-Cloud Angelfish
- Shatterjaw Shark
- Pumice Puffer
- Basalt Behemoth
The final two entries are the exotic Veiled Charybdis and the apex Skolopendra. Those are the ones with confirmed catch conditions worth planning around.
| Entry | Bait | Conditions |
|---|---|---|
| Veiled Charybdis | Meteor / Stag Beetle | Night |
| Skolopendra | Kraken Tentacle | Rain or Foggy, Autumn or Winter |
Unlock access to the Obsidian Trench first
You cannot fish a single trench entry until the Abyss Gate is open, and that takes a full questline rather than a boat ride. The whole thing starts on dry land.
| Descendant | Layer |
|---|---|
| Ignis | Volcanic Vents |
| Glacius | Challenger’s Deep |
| Tenebris | Abyssal Zenith |
| Luminis | Calm Zone |
| Resonus | Veil of the Forsaken |
Manage Trench Suppression while you farm
The instant you cross into the Obsidian Trench, Trench Suppression takes effect as an environmental debuff. It triggers automatically without asking permission and is the primary reason farming sessions finish early.
The counter is scattered around the layer in the form of glowing white crystals. Interacting with one temporarily purges your suppression level, so mentally map a few of them before you settle into a fishing spot. Bestiary grinding means long stretches in one place, and that is exactly when suppression becomes a problem.
Fill the first ten entries quickly
The ten named species are standard catches. There is no gimmick to them, so the only real variable is how many lines you can get in the water per minute.
If you own the Toxinburst Rod, use it here. Its passive frequently pulls in several extra fish alongside the one you reeled, which fills silhouettes far faster than casting one at a time. The harpoon is the fallback and works fine for heavier targets like the Tectonic Toadfish.
Keep cycling until only two silhouettes are left on the page. Those will be the exotic and apex entries, and both need dedicated setups rather than casual casting.
Catch Veiled Charybdis in the trench rivers
Charybdis is hooked in the rivers inside the trench, and hooking it spawns the Veiled Charybdis encounter. This is not a normal reel. A special high-stakes minigame starts, and losing control means being dragged into the deadly water.
Whirlpools are the hazard to watch. They strip away your rod control mid-reel, so react to them the moment they appear instead of fighting through. Run the attempt at night with Meteor or Stag Beetle bait to line up with its listed preferences.
One successful catch fills the exotic entry. You are not done with it, though, because the same fish is the key to the apex entry.
Awaken and catch Skolopendra for the final entry
Skolopendra does not spawn on a timer. You summon it by catching 4 to 6 Veiled Charybdis. Once you hit the threshold, every crystal in the trench turns deep red and an alert announces that Skolopendra has risen.
The fight runs as its own boss minigame with mysterious effects layered on top, so treat it as an encounter rather than a catch. Its listed conditions are Rain or Foggy weather during Autumn or Winter, with Kraken Tentacle as the bait. Land it and the apex entry fills.
Confirm 100% completion and the bobber reward
You will know it worked without hunting through menus. An on-screen announcement confirms the Obsidian Trench Bestiary is 100% completed, and the Obsidian Chunk Bobber unlocks alongside it. Open the bestiary with H and the trench page will show every silhouette filled in.
Buying the Chasm-Stalker Rod
Conquering the Obsidian Trench and defeating Skolopendra unlocks the ability to purchase the Chasm-Stalker Rod. Interact with the crystal prompt in the trench and the rod becomes available from the shop.
It arrives with a new mutation, a set of strong passives, and a streak system that exists only on this rod. That streak mechanic is the reason it behaves differently from everything else in your inventory, and it pairs neatly with the trench species you just spent hours cataloguing.
