Many Trainers abandon their Psybull on the curbside because they have trouble taking care of a Psybull's many tantrums that result from their headaches. Devoted Trainers who take care of their Psybull will have a loyal, lifelong partner.
By baring its fangs and making a scary face, it sends smaller Pokémon scurrying in terror. When its headache intensifies, it starts using strange powers.