Umm. There's a sort of irony about writing parodies of the Marines Hymn, because it's a sort of counter-parody, itself. The original is out of an Offenbach operetta, & it's a lampoon of the police. Dunno all the words, but one bit (in translation) sticks in my mind. After explaining how they manage never to actually have to deal with dangerous criminals:

But, when we find a helpless woman
Or little boys who do no harm,
We run them in, we run them in [bis]
To show them we're the bold Gendarmes.