Rarity

Rarity is a count that indicates a slug species' level of rareness.

Levels of Rarity

So far, slugs are seen classified into 1 of 6 levels of rarity: "Common", "Uncommon", "Rare", "Extremely Rare", "Ultra Rare" or "One-of-a-kind".

1. "Common": indicates that a species is commonly found and comes in large numbers.
2. "Uncommon": indicates that a species comes in large numbers but can be tricky to spot.
3. "Rare": indicates that a species is large in numbers but can only be easily found in certain areas.
4. "Extremely Rare": indicates that a species is few in numbers and can only be found in a certain area.
5. "Ultra Rare": indicates that a species is very few in numbers with there almost being no chance to spot more than one of each species, let alone spot even one.
6. "One-of-a-kind": indicates exactly what it says, only one of each species exists in all of existence.

Rarity Chart

This is a chart of all slugs and their rarities:

Rarity	Slugs	Ghouls
One-of-a-kind	• • • • • The Universal Slug
Ultra Rare	• • • • • •	• • Cryscada • Gorgemelter •
Extremely Rare	• • •	• Vexlet • • Ghoul Geoshard
Rare	• • •	• • • • • Doomspiker • Hoverblade • • Megabreaker • • Transplitter • Disastiped
Uncommon	• • • • • • • • • • • • • Glowbyss • Spikeshade	• • • • • • • Vamparo • • • • • • • • Quicksalvo • Sand Mangler
Common	• • • • • • • • • • • • • • • • • • • •
Unclassified	• Dustpuff

Trivia

• Oddly enough, rarity levels also refer to power levels
• Officially Tazerlings are classified as Common slugs, but oddly enough in the episode Roboslugs, they're seen classified as Uncommon on Quintin's database.