Shellos / Gastrodon

Shellos is a sea slug-like Pokémon whose appearance changes depending on which part of the sea it is found in. Both forms have amorphous, slug-like bodies, black oval-shaped eyes with yellow outlines, minuscule, dot-shaped noses, and wide yellow lips. Like real-world sea slugs, they have mantles covering the top halves of their bodies. These mantles are outlined in yellow, similar to their eyes. Unlike real sea slugs, however, they have bulbous heads and four small feet rather than one large foot.
The West Sea form's underside is white, and its mantle is pink, with several small spike-like protrusions on its back. On its head is a ring of pink, fleshy knobs resembling the gills of a nudibranch. West Sea Shellos' appearance is theorized to have been influenced by warm ocean waters.
The East Sea form, meanwhile, sports a green underside and a turquoise mantle. Two yellow-lined, flap-like protrusions, resembling cerata, are present along its back. On its head are two white-tipped tentacles resembling rhinophores that extend away from its face. East Sea Shellos's appearance is theorized to have been influenced by cold ocean waters.
Shellos lives along seashores; its color becomes more vibrant the better quality of the waters it lives in. It is also believed that Shellos's diet, which consists of plankton, also influences its form, though this has yet to be proven. The physical differences between both forms appear largely cosmetic; no significant changes in capabilities have been observed. While it can travel onto land, it can only stay on the shore for a limited time before its skin dries out. When Shellos' squishy body is pressed or squeezed, or when Shellos senses imminent danger, a mysterious purple fluid — theorized to be a kind of stress-induced greasy sweat — will ooze out of its body. This fluid is its defense mechanism against enemies; although harmless, it is very sticky and hard to wash off. Shellos has a friendly disposition and is said to have great regenerative capabilities. West Sea Shellos can extend their necks to incredible lengths. It is unknown if the East Sea form can do this as well. This species once had a shell on its back long ago and is considered a close relative to Pokémon such as Shellder.

Shellos

West Sea Shellos: It used to have a shell on its back long ago. This species is closely related to Pokémon like Shellder.


East Sea Shellos: A recently published research paper states that this form of Shellos is gradually decreasing in number.

---

Armor Class	13
Hit Points	2d8+2
Speed	20 ft., Walking	15ft., Climbing	20 ft., Swimming
Strength	13 (+1)
Dexterity	10 (+0)
Constitution	16 (+3)
Intelligence	6 (-2)
Wisdom	10 (+0)
Charisma	10 (+0)
Damage Vulnerabilities	Electic	Grass
Damage Resistances	Fire	Ice	Steel
Water
Saving Throws	Constitution d20+3
Skills	Survival d20+0
Languages	Aquan
Challenge	2 (450 XP)
Special 1	Storm Drain	If Shellos or an ally within 30 ft.,	is targeted with a direct water attack
Shellos may use a reaction to redirect the target to itself	and take half of the damage from its hit
Action 1	Mud-Slap	Ranged Weapon Attack	10 ft., one target
d20+1 to hit	Hit: 1d6+1 ground damage	Shellos hurls mud into the face of its target.
Action 2	Mud Sport	Self	Range 15 ft., radius
Shellos kicks up mud around itself	For the remainder of the battle	Electric-type attacks targeting anyone within 15 ft., deal half damage.

Gastrodon is a sea slug-like Pokémon. Much like its pre-evolved form, it has a slug-like body with a round head and a mantle covering the top half of its body. It has six stubby legs and two black eyes with white pupils, with a mark imitating a third eye appearing on its forehead. A yellow stripe runs along the edge of its mantle, through its two lower eyes, and around the back of its head. Like Shellos, Gastrodon has two forms based on the sea it lives in.
In its West Sea form, it has a pair of large tentacles on its head that curve upward and a smaller, straighter pair on its neck. Its underside is pink, while its mantle is brown, with three pink spots on each side of its back. There are also two lumps on its back, resembling the cerata on real-life sea slugs.
In its East Sea form, it retains the head tentacles it had as a Shellos, which are now fully green and angled slightly further upward. Its underside is turquoise, while its mantle is forest green with two turquoise spots on each side. It has a pair of yellow, fin-like cerata on its back and a wavy yellow line bordering its side and rear.
Gastrodon and its pre-evolution Shellos are examples of allopatric speciation, although the two forms can still breed with each other. It is also a relative of Shellder and Cloyster. When threatened, it oozes a purple liquid and flees. While not poisonous, the fluid is very bitter and sticky. Its mucus-coated body is soft and squishy yet surprisingly resilient, and it leaves behind a trail of sticky slime when moving on land. It also has strong regenerative capabilities that allow it to recover from injuries or dismemberment within a few hours. In ancient times, it had a shell on its back, which gradually became a thin yet hard vestigial plate.
Gastrodon lives in shallow tidal pools, beaches, and rocky shorelines. Its diet consists mainly of plankton, but it is occasionally known to move onto land to look for other foods, such as beach sand. When it finds prey, it melts it with mucus before eating them. While Gastrodon cannot stay out of water for too long due to its body being highly vulnerable to dehydration, it becomes more active during cloudy or rainy weather. It has been found on far-off mountains during times of constant rain. The two forms of Gastrodon are known to engage in heated conflict with one another. West Sea Gastrodon was much more numerous in the past than it is in the present. Conversely, East Sea Gastrodon's population has visibly increased in population as of late.

Gastrodon

West Sea Gastrodon: Its whole body is sticky with mucus. In the past, this form of Gastrodon was by far the more numerous one.


East Sea Gastrodon: They normally inhabit rocky seashores, but in times of continuous rain, they can sometimes be found in the mountains, far from the sea.

---

Armor Class	14
Hit Points	6d12+2
Speed	20 ft., Walking	15ft., Climbing	20 ft., Swimming
Strength	16 (+3)
Dexterity	13 (+1)
Constitution	20 (+5)
Intelligence	6 (-2)
Wisdom	12 (+1)
Charisma	10 (+0)
Damage Vulnerabilities	Grass
Damage Resistances	Fire	Poison	Rock
Steel
Damage Immunities	Electric
Saving Throws	Constitution d20+5	Strength d20+3
Skills	Survival d20+1
Languages	Aquan	Terran
Challenge	9 (5,000 XP)
Special 1	Storm Drain	If Gastrodon or an ally within 30 ft.,	is targeted with a direct water attack
Gastrodon may use a reaction to redirect the target to itself	and take half of the damage from its hit
Action 1	Mud-Slap	Ranged Weapon Attack	10 ft., one target
d20+3 to hit	Hit: 1d6+3 ground damage	Gastrodon hurls mud into the face of its target.
Action 2	Mud Sport	Self	Range 15 ft., radius
Gastrodon kicks up mud around itself	For the remainder of the battle	Electric-type attacks targeting anyone within 15 ft., deal half damage.
Action 3	Water Pulse	Ranged Weapon Attack	120 ft., one target
d20+3 to hit	Hit: 3d6+3 water damage	Gastrodon attacks with a pulsing blast of water	Target must succeed DC 15 Constitution saving throw
On a fail, they become confused
Action 4	Mud Bomb	Ranged Weapon Attack	60 ft., one target
d20+3 to hit	Hit 2d8+3 ground damage	Gastrodon launches a hard-packed mud ball at a target	Target must succeed on a DC 11 Dexterity saving throw
On a fail, they suffer a -1 on its next attack roll