Peppi Spandeck is explicitly identified as a "devout Catholic." He is apparently Italian. Mr. Spandeck is a Gotham shop owner who, inspired by Batman's example, successfully fought off a mugger who attacked an old woman.
Before the Peppi Spandeck vignette is shown, the previous material on the same page as well as the previous page feature two different individuals who are mentally disturbed or socially maladjusted, and whose were "inspired" by Batman to use violence against people they considerd criminals or wrong-doers. Peppi Spandeck is the first such individual identified as a religiously "devout" individual. His story contrasts with those of the previous individuals because Mr. Spandeck seems like such a stable person and the outcome of his conflict was rather benign and positive.
Comics are filled with countless instances of minor characters who express religiousity or demonstrate their religious affiliation in some way. This page about Peppi Spandeck is included here not because the character is of any particular importance, but because he is a good example of such characters, and also because he appears in one of the most famous comic books in history: Frank Miller's Batman: The Dark Knight Returns.
[Italian shop owner Peppi Spandeck sits behind the cash register in his shop, reading the newspaper. The headline reads "Batman."]
NARRATION: A devout Catholic, Peppi Spandeck can't say he approves of this Batman. And when he hears the woman scream down the street, he knows he should be afraid.
[Peppi looks up as he hears a woman's screaming. He grabs a wooden rolling pin.]
Instead he's looking at the alarm system that cost him two months' profits and the iron bars over his windows that make his beautiful shop look like a prison . . .
He can't feel his pulse, just below his ears. He knows he's gone crazy. But the mugger is running, afraid. Afraid of Peppi.
Nobody is hurt badly enough for this to make the news.
[We see Peppi standing alongside a woman who has been pushed down. She is kneeling and her purse is on the pavement in front of her. Peppi, still wearing his shop apron, holds the rolling pin in one hand and clenches his fist with the other hand. A mugger, a member of the violent street gang known as "the Mutants", holds his hand over his face as he runs away.]