They can evolve into other Pok mon cards. For example, if Pichu evolves into Pikachu, that Pikachu is an Evolved Pok mon, not a Basic Pok mon card. If a Baby Pok mon is your Active Pok mon and your opponent's Active Pok mon tries to attack, your opponent flips a coin. If tails, your opponent's turn ends without an attack. Baby Pok mon do not have weaknesses and they cannot be affected by status effects.
Tools says on it how it works.
Each Pok mon can have only 1 Pok mon Tool attached to it at any time.