Should I ask my cousin to return Christmas present?
That's kind of rude though. Why didn't you like the present
I don't like the present and later on I'll give it to someone else.
You don't have to like the presents that you get, but you cannot force the person who gave it to you to return it. It is not right and you should either return it yourself or give it away.
My cousin didn't even like the present that he brought for me.
It should still be your job to return it because you received it as a gift, so you have the ownership. It will come off as rude to the gift giver if you tell them to return it, because that is like telling them to return their heart and love for you. I don't think you should tell your cousin to return it.