Hebrew has a non-insult that sounds like an insult - "In your mother". It's not a polite phrase, mind you, but it's not usually used directly as an insult. It has many varied uses. it can be a shorthand for "Swear on your mother's life", mainly to express doubt (ex. "Dude, I won first prize in the lottery!" "really? In you mother!?") or a plea ("I really need a ride right now. In you mother, could you come pick me up?"). It can also be a modifier to "leave me alone", where "leave me in your mother" has about the same meaning as "leave me the fuck alone"/"fuck off".

Li mortacci tua!

Not in my language but it my local dialect "va' in mona" or "va' in figa" both translate to "go to (fuck a) p***y" and are short forms of

Va' in figa to' mare

which suggests the listener should go fuck his own mother's p***y. Very common insult in north-eastern Italy with no equivalent even in standard Italian.