In Italian, one of the many (vulgar) ways to say “Good luck !” is “In culo alla balena ! (Een kooloh ahllah bahlehnah)” which literally translates into “In the ass of the whale”.
Bonus: the response must be “Speriamo non caghi !” which simply is “Hope she doesn’t shit !”, otherwise luck won’t come to you. Makes me laugh every time.
Submitted by @myworldoflanguages