The Shellder that is latched onto Slowpoke's tail is said to feed on the host's left over scraps.
Blue
Yellow
Lives lazily by the sea. If the Shellder on its tail comes off, it becomes a Slowpoke again.
Gold
If the tail-biting SHELLDER is thrown off in a harsh battle, it reverts to being an ordinary SLOWPOKE.
Silver
Naturally dull to begin with, it lost its ability to feel pain due to SHELLDER's seeping poison.
Crystal
An attached SHELLDER won't let go because of the tasty flavor that oozes out of its tail.
Ruby
SLOWBRO's tail has a SHELLDER firmly attached with a bite. As a result, the tail can't be used for fishing anymore. This causes SLOWBRO to grudgingly swim and catch prey instead.
Sapphire
Emerald
Its tail has a SHELLDER firmly attached with a bite. As a result, the tail can't be used for fishing anymore. This forces it to reluctantly swim and catch prey.
FireRed
When a SLOWPOKE went hunting in the sea, its tail was bitten by a SHELLDER. That made it evolve into SLOWBRO.
LeafGreen
The Shellder that is latched onto Slowpoke's tail is said to feed on the host's left over scraps.
Diamond
Though usually dim witted, it seems to become inspired if the SHELLDER on its tail bites down.
Pearl
Stadium 1
If its tail is bitten by a SHELLDER, SLOWPOKE evolves into SLOWBRO. The SHELLDER seems to like its crunchy tail.
Stadium 2
If the tail-biting SHELLDER is thrown off in a harsh battle, it reverts to being an ordinary SLOWPOKE.
TCG
Dark Slowbro: It loves nothing better than to be left alone, and so sometimes ends up being manipulated by unscrupulous people.
Light Slowbro: If the Shellder attached to its tail becomes separated, this Pokémon reverts to a normal Slowpoke.
