can of worms
A complex problem, or complicated situation.
Сложная проблема; запутанная ситуация.
Let's not get into big city politics - that's a different can of worms.
His new job as a waiter turned out to be a can of worms.
Его новая работа в качестве официанта оказалась для него слишком запутанной.
A very restless, jittery person.
Joe can't sit still for a minute - he is a can of worms.