For the sake of keeping this thread civil, let's start by defining what exactly counts as a Pikaclone by four conditions:
>1. It's (most likely) a cute rodent of some kind.
>2. It's outside of Pikachu's own evolution line.
>3. It's (most likely) an electric type.
>4. It's deliberately designed to have the same type of cuteness as Pikachu himself. That is, round read, simple eyes, bright cheeks, etc.
Because of condition #2, Pichu and Raichu are automatically omitted. Pichu would otherwise count, but I give it a pass since it actually evolves into Pikachu. And Raichu was made alongside Pikachu.
>Plusle and Minun
Aside from their specific traits, their appearance and cuteness is deliberately identical to Pikachu. Clones.
>Pachirisu
It's a cute electric rodent, but it's a blue squirrel. Not as blatant of a clone, but one nonetheless.
>Emolga
Also an electric rodent, but has a secondary type (flying) and is a different species.
>Azurill, Marill and Azumarill
Literally just Pichu, Pikachu and Raichu but blue with different types.
>Dedenne
Electric rodent (Fairy secondary). The most blatant Pikaclone.
>Togedemaru
The second most blatant Pikaclone. An Electric rodent (Steel secondary), and even has the lightning bolt tail, but its silver color and weird spike things make it a little more unique.
>Mimikyu
Not at all. Type is wrong (Ghost/Fairy) and it's not a rodent of any kind. In-universe it's trying to invoke the same cuteness of Pikachu, but Mimikyu is cute for an entirely different reason, the "I want to hold it and protect it and make it happy" kind of cute.