rear/raise its head
rear its (ugly) head
Of a difficult, unpleasant problem, to present itself and force people to deal with it. Fundamentalist extremism has been rearing its head all around the world over the last couple years. I can't believe tax day is already rearing its ugly head again.
rear its heador
raise its head
COMMON If something unpleasant rears its head or raises its head, it starts to appear or be active, often when it had stopped or been hidden for a period. Now the same ugly forces of racial hatred are beginning to rear their heads again. The familiar pattern of violence is raising its head once again in the region. Note: People often say that something unpleasant rears or raises its ugly head. We will not allow hooliganism to rear its ugly head again.