The biggest questions are Pichu, Raichu, Marill, and Mimikyu

Plusle, Minun, Pachirisu, Emolga, Dedenne, Togedemaru, Morpeko, Pawmi, Pawmo and Pawmot

Makes sense that you'd know it!

I mean like i just had alot of pokemon websites open

Raichu is literally its evolution, so it doesn't really count. Pichu was just made to introduce baby Pokémon.

Yep.

Pichu is also part of pikachu evolution too

Don't some people literally call Marill "Pikablu"?

That's why I mentioned it!

Personally I'd only consider a couple of them pikaclones if they are related to pikachu (with the exception of mimikyu since it's literally THE pikachu impersonater)

Raichu, Pichu (technically evolutions), Dedenne, Alolan Raichu, plusle, minun, and mimikyu

Mimikyu, Plusle, Minun, Pachirisu, Dedenne, Pawmi, Emolga, Togedemaru

any electric rat

Pichu and Raichu aren't clones as they are the same species as Pikachu
The others. Yes

Electric type based on a rodent