Graduation

How do I convince my parents to let me get an animal for graduation? I'm going into highschool. They told me they are getting me something obviously but I want it to be either a basset hound puppy, a budgie parakeet, or a chinchilla and I would pay for...

the accessories for all the animals listed above. What now?

Be really good at home and at school and do extra chores to show you are responcible for being able to maintain a pet.