[Mardur]

Conspiracy theory (Gen I)

Although most of this is fan speculated, It is believed that the player inadvertently causes the death of Blue's Raticate on a battle on the S.S Anne ship. Raticate, after the battle is critically injured, and due to confusion on the boat and crowdedness, Blue is unable to access a Pokémon center, which ultimately leaves Blue stuck on the S.S Anne as it departs Vermillion. Later in the game, the player and Blue confront each other in Lavender town, only to engage in a battle where Raticate seems to be taken off Blue's team. However, it is speculated that Blue is in Lavender town for the purpose of laying his deceased Raticate to rest. In the dialogue prior to the battle, Blue states: "Hey (player) why are you here? Hey your Pokémon don't look dead! I can at least make them faint!".

All of this is likely false however, since the disappearance of Raticate is probably explained as a case of Blue just taking Raticate off his team.