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Beginner, boss survival, exploration, farming, and randomizer build shells.
Spoiler-light guide
Mina the Hollower Bosses and Secret Bosses
This page now has two modes: a spoiler-light prep checklist for normal progression, and a full-spoiler secret boss table for players chasing rewards, trinkets, health upgrades, and 100% completion.
Quick Answer: There are 25+ bosses and mini-bosses, with post-launch guides and wikis converging around 28 bosses including 9 secret bosses. If you only want high-value optional rewards, start with Midden, Maxi, Armand, Willis, Dark Deluxy, Mirren, Evra, Dugin, and Thalassion.
Spoiler-Light Hint: Full secret boss spoilers start in the first table. Stop after the prep checklist if you want to discover optional encounters yourself.
Secret Boss Locations and Rewards
These optional fights are the highest-intent boss searches right now because they hide trinkets, Trinket Bags, Spark/Health upgrades, and shop or quest progression. Use the verification column before treating a route as final.
| Boss | Location | Trigger | Reward | Prep tip | Spoiler | Verification |
|---|---|---|---|---|---|---|
| Midden | Queensbury: Ancestral Chamber | Open the 2-Plasma-Vial door, then insult him | Fly Bait Trinket | Use a normal combat loadout; low mechanical complexity compared with later secrets | Medium | Cross-source community verified |
| Maxi | Return route from Queensbury Crypt to Ossex | Enter Ossex from the right after clearing the first dungeon | Trinket Bag | Burrow often and treat the fight as a spacing check | Medium | Cross-source community verified |
| Armand | Ossex blacksmith lower area | Try to buy a second item from Legovich, then follow Armand's refusal event | Blacksmith service restored | Lead lava onto his path so normal attacks become more effective | Medium | Cross-source community verified |
| Dugin | Southern Outskirts or Western Hills encounter spots | Talk to Ack and Dak after Queensbury; help them twice when the randomized encounter appears | Lace Glove Trinket | Track both encounter attempts before marking the chain done | High | Community reported |
| Willis | Ossex: Bowery music hall | Complete the frog-in-a-bucket band chain, pay 100 Bones for travel, then speak to the pirate shark | Pneumatic Armlet Trinket | Stun him, then throw him into the crowd for damage windows | High | Cross-source community verified |
| Dark Deluxy | Windy Generator return route | Open the two-Spark door, escort Luxy, then fight and heal her | Spark Container | Fast boss; slower weapons need conservative burrow timing | High | Cross-source community verified |
| Mirren | Coltrane Peak: Frostbite Woods | Reach the abandoned carriage near the Underlab route and tell her you are there to help | Blinking Glass Trinket | Dodge during clone dives before committing to attacks | High | Community reported |
| Evra | Radiant Manor: Courtyard eastern gap | Use traversal tools to reach the gate, spend three Vials, then enter the fight | Health Rose | Clear skeletons so the mount has fewer ways to trap you | High | Community reported |
| Thalassion | Fishing quest chain | Progress the fishing collection until the hidden aquatic boss encounter opens | Final Fish part / Gilded Rod upgrade | Small arena; take single-hit punish windows and respect waves | High | Community reported |
Main Boss Route Snapshot
| Route point | Known encounter | Why it matters | Current status |
|---|---|---|---|
| Opening ship / sea | Nether Kraken sequence | Teaches weapon basics before Tenebrous Isle opens | Walkthrough-source verified |
| Loner's Landing / Southern Outskirts | Hulk Trooper-style early boss | First real spacing and melee pattern check | Community walkthrough verified |
| Ossex gate | Thorne | Unlocks wider Ossex access after a multi-phase fight | Community walkthrough verified |
| Queensbury Crypt | Duchess of Queensbury | Major early dungeon boss and Duke/Proto Spark follow-up route | Cross-source community verified |
| Queensbury side path | Midden | Secret boss that doubles as a trinket source | Cross-source community verified |
Boss Prep Checklist
Before each boss attempt, run through this checklist. If you fail three times in a row, change one item and retry.
| Prep item | Question to ask | What to change |
|---|---|---|
| Weapon recovery | Can I safely recover after a miss? | Switch to a more familiar or lower-commitment weapon. |
| Trinket balance | Am I dying before learning the pattern? | Use defensive or healing-support trinkets like Mandrake Root or Vial Pouch. |
| Sidearm choice | Do I need distance or interruption? | Pick a support tool that creates one safe window. |
| Healing timing | Am I healing during panic? | Heal only after a clear boss action, not while guessing. |
| Bones/upgrades | Am I under-upgraded for this area? | Farm only if route notes show a repeatable safe loop. |
| Burrow usage | Am I using burrow reactively or proactively? | Practice burrow timing in safer rooms first. |
Boss Strategy Notes
- Watch first: Spend one attempt just watching movement and patterns without attacking heavily.
- Burrow timing: Most boss attacks have burrow windows - learning these is more important than perfect DPS.
- Phase awareness: Multi-phase bosses often change patterns at specific health thresholds.
- Panic healing: Healing during unsafe moments often leads to more damage taken than healed.
- Build swapping: It's normal to switch from exploration builds to boss-focused builds before major encounters.
Common Mistakes
- Trying to out-damage a boss before understanding its rhythm.
- Changing every part of a build after one bad attempt.
- Reading full spoilers before testing a preparation change.
- Treating community boss counts as final without checking patch notes or your own route.
Related Entities
- Bosses
- Mini-bosses
- Secret bosses
- Weapons
- Trinkets
- Healing
Last Updated: June 6, 2026
Unofficial fan-made guide. Not affiliated with Yacht Club Games, Steam, or Valve.