Wiktionary
holy crap
interj. (label en idiomatic slang vulgar) An expression of amazement: holy cow, holy shit.
Wikipedia
Holy Crap
"Holy Crap" is the second episode of the second season of the FOX animated television series Family Guy, a holdover from the first season. It originally aired on September 30, 1999.
The episode features Peter's devoutly religious, recently retired father Francis coming to visit, though he is intolerant of the others and makes life miserable for the rest of the Griffin family. Peter tries to bond with him, since Francis had always been neglectful, and when all else fails, he resorts to kidnapping the Pope to settle their conflict.
The episode was rated TV-14 (D) for suggestive dialogue.