The best replacement for pikachu is raichu.

The best alternatives to pikachu are rated as following:
★★★★★  raichu
★★  raichu pokemon x
★  jolteon
★  blanka
★  mewtwo
★  latios
★  pikachu
★  dragonite
★  charizard
★  zapdos
★  electrike
★  luxray
★  raichu emerald
★  electabuzz
★  snivy
★  ampharos
★  bulbasaur
★  helioptile
★  jolteon fire red
★  shinx
★  emolga
  raichu episode
  kirby
  pichu
  magneton
  onix
  regice
  dedenne
  voltorb
  manectric
  raichu better
  venusaur
  squirtle
  magnemite
  lucario
  mareep
  eevee
  pachirisu
  new pikachu
  meowth
  charmander

Your alternative for pikachu is not listed? Suggest!
Speaking about pikachu, one probably shouldn't forget about light ball.

Other search terms related to pikachu and their ratings are:
★★★★★ light ball
★★★★★ volt tackle
★ extremespeed
★ pokeball
ash
misty
You have in mind a companion for pikachu and it is not yet here? Propose!



Google Trends

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pikachu
raichu
raichu pokemon x