Saint Anthony? Who's Saint Anthony?

There was a part in Catch-22 in which the above phrase is repeated quite a few times by different characters for a humorous effect.

I didn’t think much about the joke until I read Breakfast of Champions, in which two other characters refer to him again without knowing who he is, and it is intended for a humorous effect again.

Is there some reason why both Heller and Vonnegut chose Saint Anthony?

According to a quick search, St. Anthony was known for converting heretics, as well as being the patron saint of:

[li] those afflicted with St. Anthony’s fire - ergot poisoning[/li][li] those who find their lives completely uprooted and sent in a new and unexpected direction[/li][li] amputees, barren women, lost articles and domestic animals[/li][li] lost items and impossible causes[/li][li] sailors, travelers and fishermen[/li][li] the poor[/li][li] wine merchants[/li][li] writers[/li][li] pigs[/li]
My WAG (and I have not read the books in a long time) - the characters in question were lost causes, St. Anthony’s specialty.

St. Jude was the patron saint of lost or hopeless causes. Poor St. Anthony of Padua was the patron saint of lost items- as in misplaced shoes, missing wallets, misdirected luggage etc.

I think every Catholic my age could relate to George Carlin’s panicky prayer, “Pleeeeease, St. Anthony, I NEEEED my keys, man!”

In Catch-22, Doc Daneeka describes a beautiful female patient of his who wore a Saint Anthony medal around her neck, and remarks that hanging between her breasts must present a terrible temptation for Saint Anthony.

The saint in question here is not Anthony of Padua, but Anthony of the Desert, who was famously and elaborately tempted by Satan while living as a hermit. Everyone from Bosch to Dali has painted a ‘Temptation of St. Anthony’,
and there’s a novel of that title by Flaubert.