Where can I find Custos in Mongil: Star Dive?

Custos spawns in the Elendor region. It is a boss encounter — expect a longer fight with HP-phase mechanics.

What element is Custos weak to?

Custos is weak to Ice damage. Build a team that leverages those elements for the fastest kills.

What does Custos drop?

Custos doesn't drop any items directly. Tame it for codex rewards instead.

Yes — Custos can be tamed. Hitting 5 taming milestones unlocks new codex entries. Reach the final tame to recruit it as the Custos monsterling.

Yes — Custos is a boss-tier encounter with 10 HP phases. Bring elemental counters and don't underestimate the phase transitions.

Mongil Codex · Boss · Elendor

Custos

Level 1

Earth
Boss
Elendor

Custos is a boss encountered in Elendor. It cycles through 10 HP phases during the fight.

Last updated May 2026 · Verified for the latest Mongil: Star Dive build

Last reviewed by Trakan — May 13, 2026

Stats

HP: 14,178Hit points
ATK: 33Attack
DEF: 120Defence

Elemental weaknesses

HP phases

Custos cycles through 10 HP phases during the fight. Each phase threshold triggers new mechanics and survives until the boss drops below the next checkpoint.

Phase 1HP 100% → 90%
Phase 2HP 90% → 80%
Phase 3HP 80% → 70%
Phase 4HP 70% → 60%
Phase 5HP 60% → 50%
Phase 6HP 50% → 40%
Phase 7HP 40% → 30%
Phase 8HP 30% → 20%
Phase 9HP 20% → 10%
Phase 10HP 10% → 0%

Taming tiers

Tame Custos repeatedly to unlock codex entries and earn rewards. Milestone tames mark new lore entries.

×1Entry 1Nyanners EXP ×750
×2Nyanners EXP ×750
×3Entry 2Nyanners EXP ×750
×4Nyanners EXP ×750
×5Entry 3Nyanners EXP ×750
×6Nyanners EXP ×750
×7Entry 4Nyanners EXP ×750
×8Nyanners EXP ×750
×9Nyanners EXP ×750
×10Entry 5Nyanners EXP ×750

Codex milestones at tames 1, 3, 5, 7, 10.

Monsterling

Tame to recruitCustosOpen monsterling page →

Comments

Guides

In-house guides re-tested every patch.

Guides and articles content remains in English.

Mongil: Star Dive — Beginner Guide

Adventure map, jumping, gathering and the first-week checklist — every core mechanic the in-game tutorial walks you through, written in one place.

Trakan

Updated Patch 1.0

Reroll Guide — Best Targets and Stop Conditions

Best characters to chase on a fresh account, the fastest reroll path, and when the meta says you should stop and commit.

Trakan

Updated Patch 1.0

Best Team Comps — Destroyer, Slayer and Flex Slot

How team building actually works in Mongil — the Destroyer + Slayer + flex template the Stagger system rewards, when to break it for element-locked counters, and the Brawler-led sustained-DPS variant.

Trakan

Updated Patch 1.0

Combat Basics — Hold Attacks, Switch Skills, Ultimates

Basic attacks, special skills, switch skills and ultimate timing — the hold-input combat system explained without the in-game popup spam.

Trakan

Updated Patch 1.0

Frequently asked

Where can I find Custos in Mongil: Star Dive?: Custos spawns in the Elendor region. It is a boss encounter — expect a longer fight with HP-phase mechanics.
What element is Custos weak to?: Custos is weak to Ice damage. Build a team that leverages those elements for the fastest kills.
What does Custos drop?: Custos doesn't drop any items directly. Tame it for codex rewards instead.
Can Custos be tamed?: Yes — Custos can be tamed. Hitting 5 taming milestones unlocks new codex entries. Reach the final tame to recruit it as the Custos monsterling.
Is Custos a boss?: Yes — Custos is a boss-tier encounter with 10 HP phases. Bring elemental counters and don't underestimate the phase transitions.