After you have chosen a Pokemon in Pokemon Mystery Dungeon: Rescue Team DX you are able to pick a partner for them from the remaining 15 Pokemon. The only limitation is you that you cannot select a Pokemon of the same type. Check out our How to Choose the Best Partner guide to find out how you can get the perfect partner Pokemon.
The most important thing you need to consider when choosing a partner is move coverage, you want to pick a Pokemon that will complement your Starter by dealing super effective damage to the type(s) your Starter is weak to. Normal type Pokemon are only weak against Fighting types. In our opinion the best partner to choose is probably Pikachu as he is able to deal super effective damage to Flying types. Otherwise you may want to consider Psyduck as he has access to Psychic type moves that are super effective against Fighting types.
Below is a list of all the Pokemon and their ideal partner type. Remember that you cannot have a Starter and Partner Pokemon to be the same type.
• Pikachu
Water or Grass
• Charmander
Electric, Grass, or Water
• Mudkip
Fire or Ground
• Cyndaquil
Electric, Grass, or Water
• Totodile
Fire or Ground
• Psyduck
Fire or Ground
• Squirtle
Fire or Ground
• Torchic
Electric, Grass, or Water
• Eevee
Pikachu or Psyduck
• Skitty
Pikachu or Psyduck
• Cubone
Electric, Grass, or Fire
• Meowth
Pikachu or Pysduck
• Bulbasaur
Electric or Water
• Chikorita
Electric, Water, or Fire
• Machop
Electric
• Treecko
Electric, Water, or Fire
Check out our How to Evolve Pokemon guide to find out the requirements to evolve Pokemon in Pokemon Mystery Dungeon: Rescue Team DX.