Spiky pichu

No. She's exclusive to an event in HGSS (a game that I never received), where she kinda replaced Celebi. She is much-maligned because of her sheer uselessness. She cannot evolve or be transferred between games, this leaving her stuck in whatever savefile you ran when you caught her and stuck with lackluster everything.

There was also an event where you could receive a Pikachu-colored Pichu, but I'll let this slide because it's just the shiny form of a rare Pokemon, and not many people can be expected to find shinies unless they are guaranteed. You'd have to be crazy-determined to go through all the effort of getting a shiny Pichu otherwise.