My autistic brother is just an a-ss hat?

Can you show your parents what he does when you try to get him to do his work? Have you told them what you said in this post? If none of that will work, try this. Instead of threatening bad stuff if he doesn't do it, give good stuff. Promise him he can have ice cream (or something like that) if he does his work correctly, or that the quicker he gets them all done right, the quicker you two can play a game together. Make it a positive experience where he gets a reward when he's done and he might start doing his work. Good luck!