His badass look makes everyone think he's so cool.

badass 是俚语，由 bad（坏的）和 ass（屁股）组成，字面意思是"坏屁股"。在俚语中用来形容某人非常酷、厉害或强硬，带有叛逆不羁的意味。badass look 就是指"看起来很酷很叛逆的样子"。