Kill it Before it Lays Eggs

A common response to something so horrible, annoying, disgusting, and/or crazy that it needs to be killed before it makes more of itself, hence "lays eggs."

When someone says this it's a reference to an individual so stupid, annoying, etc that it should not be existing and is better off being killed before it reproduces (before it lays eggs = before it makes more of itself/ has youngsters as annoying/stupid as itself)