How about this? I'm going to take all the credit for a group project.
What are you thinking? Why would you take all the credit?
I don't want to share with anyone else. I've always been like that.
It's good that you contributed to a successful group project, but how do you think the others will react to your grossly misrepresenting their contributions? It's not only unfair, but you will get a reputation for being an untrustworthy jerk.
I'm not afraid. I think this is the perfect time to show off my abilities to everyone.
You will be critiqued and rightfully so. This is not a behavior that is standard, you would really suffer bad consequences for this, trust me you will. Maybe even worse than that.