Morveth's Treasure Gun is one of the strongest harpoon guns available during the mid-to-late game grind in Roblox Abyss. It's locked behind a four-part questline given by the Morveth NPC, who lives inside a hidden cave at the edge of the Forgotten Deep biome. Finishing the full questline and purchasing the gun also awards the Morveth's Treasure badge — one of 51 total badges in the game.
Quick answer: Reach Morveth's Cave at 260m depth in the Forgotten Deep, complete all four Morveth quests (catching mutated fish and hitting level milestones up to Level 20), place the four Ruby Runes into the monoliths, then buy the gun for $82,500.
Morveth's Cave Location
Morveth's Cave sits inside the Forgotten Deep biome, but getting there requires a tube with at least 100 oxygen capacity and a 260 maximum depth rating. If your tube can't handle those numbers, you'll need to upgrade before attempting the trip.
Step 1: From the main spawn area, head toward the Leaderboards. Enter the ocean from the right side of the Leaderboards and swim straight ahead. You'll pass a submarine on your left — keep going in the same direction.
Step 2: Continue until you reach the boundary of the Forgotten Deep biome. An "Ocean" message will appear on screen. At that point, dive straight down to 260 meters.
Step 3: Look for an underwater waterfall. Swim through it to enter Morveth's Cave. Once inside, go straight and then take a left to find the Morveth NPC standing near a cluster of monoliths. You'll also see Morveth's Treasure Gun displayed nearby, but it can't be purchased yet.
Morveth's Questline — All Four Quests
Speak to Morveth to begin his questline. Each quest has two objectives: catch a specific type of mutated fish and reach a certain player level. Completing a quest rewards one Ruby Rune along with other items. You need all four Ruby Runes to unlock the gun.
| Quest | Fish Requirement | Level Requirement |
|---|---|---|
| Morveth's Quest 1 | Catch 2 Coral-mutated Fish | Level 5 |
| Morveth's Quest 2 | Catch 3 Metal-mutated Fish | Level 10 |
| Morveth's Quest 3 | Catch 3 Albino-mutated Fish | Level 15 |
| Morveth's Quest 4 | Catch 4 Transparent-mutated Fish | Level 20 |
The fourth quest is the most time-consuming. Transparent-mutated fish are among the rarest catches in Abyss, and your best chance of finding them is to fish in the deepest areas of the ocean. Plan to spend extra time on this step.
Activating the Monoliths and Buying the Gun
Once all four quests are done and you have four Ruby Runes in your inventory, return to the Morveth NPC inside the cave. Four smaller monoliths surround him — place one Ruby Rune into each. When all four are active, the larger central monolith beside Morveth lights up and unlocks the Treasure Gun for purchase.
The gun costs $82,500 in-game currency. After buying it, you'll automatically receive the Morveth's Treasure badge on your Roblox profile.
Morveth's Treasure Gun Stats
| Stat | Value |
|---|---|
| Price | $82,500 |
| Damage | 240 |
| Cooldown | 2.1s |
| Control | 0.85 |
With 240 damage and a 2.1-second cooldown, the Treasure Gun hits a solid balance of power and fire rate for its price tier. It deals 50 more damage than the Magroot Gun while sharing the same cooldown and control values. The Magroot costs $35,000 less, so it's a reasonable budget alternative, but the extra damage from Morveth's gun noticeably speeds up progression through tougher biomes.
How to Confirm You Got the Badge
The Morveth's Treasure badge appears on your Roblox profile under your badges list immediately after the purchase. In-game, you can also check the Achievement Menu — the rosette icon on the left side of the screen below your cash display. Completing certain badges lets you claim a 5x Star Shard reward from that menu, so it's worth checking after any major unlock.
Morveth's Treasure Gun is one of the more rewarding quest-locked weapons in Abyss, especially for free-to-play players who want strong gear without relying on premium purchases. The grind to Level 20 and the hunt for Transparent-mutated fish take real time, but the payoff is a reliable harpoon gun that stays useful well into the late game.