Catch a Monster S Grade Monsters Guide (2026)

S grade is the highest rarity tier available through wild catches and boss eggs in Catch a Monster. But in 2026, many players are confused: if S grade is so rare, why does a Huge A grade sometimes seem stronger? This guide explains the S grade system, how to get S rank monsters, and whether they are worth pursuing given the current meta.

What is S Grade?

Monster grades determine the base stat quality of a monster when it is caught or hatched. The grade scale from lowest to highest:

An S grade monster has the highest possible base stats for its species when considering only grade — no mutations applied.

Why Huge A Can Beat S Grade

This surprises many players: a Huge A rank monster can be stronger than a plain S rank.

Here is why:

The Huge mutation applies a significant multiplier to both HP and ATK that stacks on top of base stats. The practical result:

A plain S grade: High base stats, no multiplier A Huge A grade: Good base stats × Huge multiplier = often comparable or higher effective stats

Example scenario:

If S grade base ATK = 8,000 and A grade base ATK = 6,500, but Huge adds +40% to A grade, the Huge A ends up at 9,100 ATK — beating the plain S grade.

Community consensus: This is considered a balance problem. S grade is far harder to obtain but not always the best practical outcome. The developers have received feedback about this discrepancy.

Is S Grade Still Worth Pursuing?

Yes — here's why:

1. Huge S grade is the best possible outcome. An S grade monster WITH a Huge mutation is definitively the strongest version of that monster in the game. The gap between Huge S and Huge A is significant.

1. S grade has the highest potential ceiling. Even without mutations, an S grade at A-rank with A+10 ascensions and good EM% will match or outperform a Huge A rank in high-investment endgame.

1. Future content may favour natural grade. As the game evolves, mechanics that scale directly off grade (not mutations) may emerge.

Practical advice: If you get an S grade — even E-rank — keep it and fuse it up. An S grade E-rank is the foundation of potentially the best monster in the game. Never sell or release an S grade.

How to Get S Grade Monsters

S grade cannot be obtained through fusion (fusing caps at B rank; A rank requires Arcane Stones, not grade rarity). You can only get S grade by:

Method 1: Wild Catch (Low Probability)

Any wild monster has a tiny base chance to spawn as S grade Luck Gamepasses improve your odds (Ultra Luck +300% is most efficient) Higher-level islands have slightly better base grade probabilities

Method 2: Boss Egg Hatching (Best Method)

Boss eggs give the highest probability of high-grade (A and S) monsters: Glazadon Egg (Glazadon boss, Frost Isle) — one of the best egg sources Tidevex Egg (Tidevex boss, Tideland Island) ShadeKnight Egg (ShadeKnight boss, Neverland Island) Frostwyrm Egg (Frostwyrm boss, Spirit Grove)

Each boss egg has a chance — not a guarantee — at S grade. Most eggs return A grade at best.

Method 3: Special Event Eggs

Seasonal events sometimes feature event-specific eggs with boosted S grade rates. Keep an eye on event announcements.

How to Maximise S Grade Chances

Use Ultra Luck Gamepass (599 Robux, +300% luck): The best luck investment for catch and hatch quality 2x EXP + Ultra Luck combo: Common high-value gamepass pairing for active players Hatch during Blood Moon: Bloodmoon weather increases mutation chances; pair with egg hatching sessions Server-hop boss routes: More Glazadon/Tidevex kills per hour = more egg chances per hour

S Grade vs. Huge A Grade Comparison

What to Do With S Grade Monsters You Already Have

1. Fuse them up to B rank using standard fusion (5x same species)
2. Use Arcane Spark Stones to ascend to A rank (17 stones per B→A fusion)
3. Work on A+10 ascension (10 Arcane Stones total)
4. Apply Chaos Potions for good EM% after any evolution
5. Keep them regardless of rank — S grade is permanently valuable

For fusion and Arcane Stone strategies, see Enhancement Guide. For the best monsters in the meta, see Tier List.*