Yo soy ayudante personal.

(I looked up Batman in a Spanish/English dictionary...apparently Batman is my personal helper.)

ayudar is the verb: to help. were you trying to say bat man?

yo tengo un hunter en mis pantalones

Yes, I was trying to say Batman. Yes, I know ayudar is the verb. Fact remains that when I Babelfished "I am Batman" that's the phrase that came up.

For words that originated in english speaking countries, you'd just say batman, and others like it - I.E. 'los blue jeans.' Just depends on what you're talking about. Iconic figures/superheroes and catch phrases are usually the same in both languages. It's hard to tell sometimes

yea if you wanted a direct translation it would be el murciélago hombre or el hombre murciélago. However you wouldn't say that. as wook said it would simply be batman.