what does oberon want titania to wake and fall in love with some vile thing?

Oberon wants the boy left to Titania by the servant lady. He casts a spell over her so he can take the boy away. Oberon wants a "hunting buddy". Tatiana will not allow this; she wants the boy to herself. There is a rivalry going on between the two; kind of like Beatrice and Benedict in Much Ado about Nothing. Oberon also thinks it funny that Titania be enamored with an ass-creature like Bottom.