Every character you meet in 100 Days at Sea falls into one of two camps. Friendly NPCs hand out tools, trades, and progression boosts once you reach them, while hostile mobs attack on sight and drop loot when you kill them. Knowing which is which before you land on an island saves both health and time.
Quick answer: There are five friendly NPC types (Survivors, the Fisherman, the MukuMuku Merchant, Glorbus, and the Penguins) and eight hostile mob groups, plus five bosses. Rescue Survivors and the Fisherman first for the biggest early gains.
Friendly NPCs and what they give you
Friendly NPCs cannot be damaged. You interact with them to rescue, feed, or trade, and each interaction pushes your run forward. Two of them, the Survivors and the Fisherman, should be top priorities because they unlock automation and free gear early.
Survivors: Captain Stephen, Doctor Madelaine, Professor Erik
Three Survivors spawn every run, each on a separate Survivor Island. You can locate their islands using the radio structure. To rescue one, walk up and press to interact, after which they teleport straight to your base and start working.
Each rescued Survivor adds +1 to your Day Multiplier and automates your base. If you bring raw materials home, they process them, and if you place machines like the crab trap, sawmill, or magnet, they run those for you automatically. The only real difference between the three is the island they appear on and their look; their behavior is identical.
The Fisherman and his trades
The Fisherman sits on Fisherman’s Island, the large island right next to your starting raft, guarded by Buku Warriors. Defeat the guards, then interact with him to free him. Rescuing him gives every player a Fishing Rod and unlocks the hut, which holds a chest that always contains a Dinghy.
After freeing him, you can trade fish for useful items. The trades run in the same order every game, and each player can complete them separately.
| Fish you give | Item you receive |
|---|---|
| Fish Fillet | Crab Trap |
| Fish Sandwich | Machete |
| Sushi | Good Sack |
| Jar of Jelly | Flintlock |
| Fish and Chips | Chowder |
| Buttered Bass | Flare |
| Calamari | Doubloons |
| Lobster Tail | Blunderbuss |
| Unagi | Doubloons |
| Shark Filet | Giant Sack |
| Swordfish Steak | Swordfish Sword |
MukuMuku Merchant (Traveling Merchant)
The MukuMuku Merchant sails up to one side of your base during the day and leaves again at night. He deals only in Doubloons, which you cannot spend anywhere else, so it pays to visit him whenever he arrives. Every item has limited stock per player, and anything you buy will not restock on later visits. If you rejoin, the shop may look refilled, but bought items stay unavailable.
He carries around 20 item types. The standout purchases are worth planning your Doubloons around.
| Notable item | Cost and stock | Why it matters |
|---|---|---|
| 10 Pearls | 500 Doubloons, once | One of the few in-game ways to earn Pearls; can also revive teammates |
| Medkit | 100 Doubloons, twice | The only way to revive a downed player |
| Rifle | 150 Doubloons, once | Reliable ranged damage for classes lacking offense |
| Ghost Sack | 250 Doubloons, once | The best sack in the game |
He also stocks Corrupt Shards, Boats, Weapons, and Building materials. Spend early Doubloons carefully, since medkits and Pearls compete for the same budget.
Glorbus, the Alien Island NPC
Glorbus is a large green alien found on one of the Alien Islands. He asks for 20 food items of any kind. Once fed, he rewards you with the Alien Food Machine, which turns five food items into Alien Soup. Alien Soup restores more hunger than regular Chowder.
Note: think before placing the Alien Food Machine down. Survivors will feed it any food item automatically, including ones you might rather eat yourself.
Penguins and the Yeti trigger
Penguins only appear on maps that spawn with the Ice Biome. There are 20 Lost Penguins scattered across several islands in the biome. Find all 20 and return each one to the Penguin Mother. Once every penguin is delivered, the Yeti Boss spawns.
Hostile mobs and their loot
Mobs attack when you get close and appear on islands, in biomes, on the open sea, and during night raids. Killing them drops materials, chests, and occasionally rare weapons. Each group has its own variants and danger level.
Ghost Pirates
Ghost Pirates are the most common enemy and raid you as early as your first night. They carry swords or guns and appear on Pirate Islands, Ghost Galleons, Pirate Raids, and Pirate Strongholds. Defeating them drops Essences used to brew potions. Variants include a Gunner, a Bombardier, and a Captain.
Buku Tribe
The Buku Tribe holds many early-game islands and drops plenty of chests and loot. Buku Bukus are among the first enemies you fight. Variants include the Buku Boku, Buku Poku, and Buku Toku. The Buku Poku has a chance to drop the Poku Poku Weapon.
Rival Survivors
Rival Survivors guard Rigs and Radio Towers across the map, using both melee and ranged weapons. Defeat and loot them for high-tier drops like Weapons, Doubloon Chests, and armor. Come prepared, since they defend their bases aggressively.
Corrupt Creatures
Corrupt Creatures appear inside Corrupted structures such as the Cargo Ship. They have high HP and hit hard, but they drop rare loot like the Corrupt Minigun, Revolver, and Saber. The full lineup includes the Corrupt Crewmate, Corrupt Officer, Corrupt Saber Yielder, Corrupt Minigunner, Chest Mimic, Red Jellyfish, and Blue Jellyfish.
Aliens
Aliens show up during Alien Raids and on Alien Islands, and they are some of the hardest enemies in the game. Keep your distance, because they deal heavy damage. They can occasionally drop the Energy Sword, a strong melee weapon for the mid to late game. The three types are the Alien, Alien Warrior, and Alien Overlord.
Sea Monsters
Sea Monsters roam the open ocean and are rarer than land enemies, but dangerous without good weapons. They include the Salamander, Shark, and Angler Fish, and they can knock you off your boat and damage you instantly. Outrunning them is usually your only option.
Biome-specific mobs
Some enemies only spawn in specific regions like the Ice or Magma biome. These include Magma Golems, Magma Snails, Wolves, and Polar Bears. They rank among the toughest fights in the game, so keep your distance and plan your attacks.
Bosses and their reward weapons
Bosses are far stronger than regular mobs and reward unique weapons or progression items. Before taking one on, stock up on healing items, bring ranged weapons, and equip good armor.
| Boss | Reward |
|---|---|
| Ancient Squid | Squid Laser |
| Yeti | Ice Staff |
| Magma Boss | Magma Staff |
| Ghost Pirate Captain | Ghost Cutlass |
| Kraken | Corrupted Minigun |
Between the friendly NPCs handing out gear and the mobs guarding the best loot, most of your progression comes down to picking the right targets in the right order. Rescue the Fisherman and your Survivors early, spend Doubloons at the MukuMuku Merchant with a plan, and only chase bosses once your healing, ranged weapons, and armor are ready.
