#0044 · Generation I
What Animal Is Gloom Based On?
Gloom is mostly a fantasy design, but its closest real animal is the Leaf Sheep Sea Slug.
Closest animal
Leaf Sheep Sea SlugConfidence
Broad or mixed-animal match
How Gloom compares to the real Leaf Sheep Sea Slug
Gloom's official category is the Weed Pokémon. AnimalDex rates its resemblance to the Leaf Sheep Sea Slug as a broad match, meaning the animal is one influence in a largely fantasy design. Gloom is a plant design rather than an animal. Its leafy, photosynthesising body keeps the leaf sheep sea slug as the nearest real comparison, a tiny animal that carries working plant chloroplasts.
The comparison covers looks and behavior cues, not biology: Gloom is a fictional Pokémon, while the Leaf Sheep Sea Slug (Costasiella kuroshimae) is a real marine invertebrate. On AnimalDex the real Leaf Sheep Sea Slug scores 4 for dominance, 2 for speed, 2 for size and 6 for intelligence, out of 100, so its strongest trait is intelligence.
Official category: Weed Pokemon. This page is an AnimalDex comparison for real-animal resemblance, not an official design-origin claim.
Meet the real Leaf Sheep Sea Slug
Costasiella kuroshimae
A tiny sea slug of the sap-sucking group, it lives on the green algae it feeds on, reported mainly as Avrainvillea. The swollen green cerata crowding its back match the colour of its food alga, so a slug sitting on it is very hard to pick out.
How to recognize it
- Rows of green, leaf-shaped cerata along the back
- Cerata often tipped with pale or coloured spots
- Two dark eyes set close together on the head
Real Leaf Sheep Sea Slug facts
- Its species name refers to Kuroshima, an island in southern Japan where it was first found.
- The common name comes from its resemblance to a small grazing sheep, with its face and the woolly look of its back.
- Diet
- Only the cell sap of the green alga it lives on. Chloroplasts from the meal are kept working inside the slug's digestive gland for a time and may supply some sugars from photosynthesis, though how much they contribute is debated.
- Lifespan
- How long it lives is not known; small sap-sucking slugs are generally thought to survive only a few months.
- Predators and threats
- Small marine predators and environmental change matter because a delicate body survives through disguise, chemistry, and habitat fit rather than force.
| Dominance | Speed | Size | Intelligence |
|---|---|---|---|
| 4/100 | 2/100 | 2/100 | 6/100 |
Gloom animal FAQ
- What animal is Gloom based on?
- Gloom is mostly a fantasy design, but its closest real animal is the Leaf Sheep Sea Slug. Gloom is a plant design rather than an animal. Its leafy, photosynthesising body keeps the leaf sheep sea slug as the nearest real comparison, a tiny animal that carries working plant chloroplasts.
- Is Gloom a real animal?
- No. Gloom is a fictional Pokémon. Its closest real counterpart is the Leaf Sheep Sea Slug (Costasiella kuroshimae), which AnimalDex covers with real field-guide facts.
- What is the real Leaf Sheep Sea Slug like?
- A tiny sea slug of the sap-sucking group, it lives on the green algae it feeds on, reported mainly as Avrainvillea. The swollen green cerata crowding its back match the colour of its food alga, so a slug sitting on it is very hard to pick out.
- Which other Pokémon are based on the Leaf Sheep Sea Slug?
- AnimalDex also pairs Oddish, Vileplume, Sunkern, Sunflora, Applin and Smoliv with the Leaf Sheep Sea Slug.
More Leaf Sheep Sea Slug comparisons in Generation I
| No. | Pokemon | Closest animal | Basis |
|---|---|---|---|
| #0043 |  Oddish | broad | |
| #0045 |  Vileplume | broad |