Should I threaten an autistic kid to make him stand up for himself?
Why take such drastic measures? Will this help them in the end?
Yes, hes socially awkward and I think gaining a little confidence will do him some good.
Wanting to help him out is commendable but you should consider how you're going about it. What you're doing can me misunderstood as disrespect and you already know you should treat disabled people with the same respect you show anyone else. Try to think of a better way to help him.
I'm also going to show him pictures of a dead whale and ask if he would rather be that whale or have a chance to have sex with a mermaid.
Yeah, I don't think that will work either. Why don't you teach him how to fight or workout together to gain muscles? Those are probably better options than threatening him or exposing him to weird images.