What does Custos do as a monsterling?

Equipped on a character, Custos triggers a link skill: "Using a Special Skill". The skill activates each time the condition is met during combat.

Tame Custos in the open world to recruit Custos. The bestiary entry above lists every spawn location.

Yes — Custos is a viable fusion ingredient. Combine it with the listed partners to create 1 different monsterling result.

What are Custos's reinforcement costs?

Custos reinforces up to level 60. Total cost: 5,025,139 EXP and 25,125,695 gold.

How many variants does Custos have?

Custos ships in 5 rarity variants — base ATK/DEF/HP scales from the lowest to the highest tier. The Variants section above lists each one.

Mongil Codex · Monsterling · #38

Custos

Element Earth

Earth
Grade 2

Custos is a rare boss-type Earth-element Monsterling. It stands 113.0–136.0 m tall and weighs 3700–4100 kg. Available in 5 variants: N (1★), N (2★), R (3★), SR (4★), SSR (5★). Base stats range from 23/36/111 ATK/DEF/HP at N to 45/70/222 at SSR. Ability: Target's DEF -8.3% for 5s upon landing a critical hit with an Earth Attack Can be fused with Gold Digger Moley Mole to produce El Dorado Guardian (20% chance).

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

Last reviewed by Trakan — May 13, 2026

Profile

Height: 113.0–136.0 m
Weight: 3700.0–4100.0 kg
Companion scale: 0.30×Display size

Link skill

Link skill · Lv. 5 · Earth

Using a Special Skill

If the Custos Monsterling is equipped, it appears when its Appearance Condition is met. It throws the condensed energy of nature, dealing Earth DMG and dragging the enemy in. It then inflicts a Bonus Effect and renders the enemy Airborne.

[Appearance Condition]
Using a Special Skill

[Appearance Info]
DMG based on equipping character's ATK: 200%
Cooldown: 8s

[Bonus Effect]
15% Neutralization RES Reduction (5s)

Damage: 200% · Cooldown: 8s

Chain-link unlocked at level 9.

Stats

Per-level ATK/DEF/HP scaling — and the reinforcement cost to reach each level. Switch rarities to see how the same level lands at higher floors; scrub the slider to see the cumulative EXP, gold, and best-fit feed mix update live.

LevelLv. 60/ 60

HP2,721+2,499 from Lv. 1
ATK818+773 from Lv. 1
DEF1,275+1,205 from Lv. 1

Reinforcement to Lv. 60

Target level: 60Lv.
Cumulative EXP: 3,768,879EXP
Cumulative gold: 25,125,695Gold

Recommended feed mix to reach Lv. 60

Variants

Custos ships in 5 rarity variants. Each variant scales the same base ATK/DEF/HP curve at different floor values. Use the stats section to scrub the per-level curve for any rarity.

N★23/36/111
N★★26/39/123
R★★★31/46/145
SR★★★★37/57/178
SSR★★★★★45/70/222

Tame from bestiary

Origin monsterCustosOpen bestiary entry →

Merge to create

Fuse Custos with these partners to produce a new monsterling.

Gold Digger Moley MoleEl Dorado Guardian20% success

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

What does Custos do as a monsterling?: Equipped on a character, Custos triggers a link skill: "Using a Special Skill". The skill activates each time the condition is met during combat.
How do I get Custos?: Tame Custos in the open world to recruit Custos. The bestiary entry above lists every spawn location.
Can I fuse Custos?: Yes — Custos is a viable fusion ingredient. Combine it with the listed partners to create 1 different monsterling result.
What are Custos's reinforcement costs?: Custos reinforces up to level 60. Total cost: 5,025,139 EXP and 25,125,695 gold.
How many variants does Custos have?: Custos ships in 5 rarity variants — base ATK/DEF/HP scales from the lowest to the highest tier. The Variants section above lists each one.