Its newly grown legs prevent it from running. It appears to prefer swimming than trying to stand.
Blue
Yellow
The direction of the spiral on the belly differs by area. It is more adept at swimming than walking.
Gold
Because it is inept at walking on its newly grown legs, it always swims around in water.
Silver
The direction of its belly spiral differs by area. The equator is thought to have an effect on this.
Crystal
The swirl on its belly is its insides showing through the skin. It looks clearer after it eats.
Ruby
POLIWAG has a very thin skin. It is possible to see the POKéMON's spiral innards right through the skin. Despite its thinness, however, the skin is also very flexible. Even sharp fangs bounce right off it.
Sapphire
Emerald
It is possible to see this POKéMON's spiral innards right through its thin skin. However, the skin is also very flexible. Even sharp fangs bounce right off it.
FireRed
Its slick black skin is thin and damp. A part of its internal organs can be seen through the skin as a spiral pattern.
LeafGreen
Its newly grown legs prevent it from running. It appears to prefer swimming than trying to stand.
Diamond
Its skin is so thin, its internal organs are visible. It has trouble walking on its newly grown feet.
Pearl
Stadium 1
The spiral on its belly is its internal organs seen through its thin skin. It is better at swimming than walking.
Stadium 2
Because it is inept at walking on its newly grown legs, it always swims around in water.