Here's what's likely happening:
* Misremembering: You might be thinking of Pikachu, Pichu's evolved form. Pikachu has pointy ears, but they're not considered "spiky".
* Fan Creation: There might be fan-made artwork or descriptions of a Pichu with spiky ears, but it's not a recognized Pokémon by the official games or lore.
To clarify, Pichu has rounded, floppy ears, not spiky ones.