I want a picture with each. The annoying rodent isn't being happy with me force feeding him Potions.
At zero happiness, Pikachu will turn its back on you in disgust
Pikachu's ear will flicker and it will be angry with you at low happiness
Pikachu will look content at moderate happiness
Pikachu will look content at above average happiness
Pikachu will have a heart floating around him at high happiness
Pikachu will have a heart floating around him at near max happiness
Pikachu will have six hearts flying around him at max happiness
Source Hope I helped :)