Dual Hook

Only one head can hold terrain at a time, so this is not a spider style multi-anchor hook. What it gives you is a free attempt. Firing the second head while you hang from the first does not drop you unless the new one actually catches something, so you can probe for a ledge above you, miss, and stay exactly where you were.

That makes it the hook for crossing a cavern ceiling or a chasm without ever touching the floor. It also reaches well beyond anything available before Hardmode, which is the part most people notice first. Mimics are the only source, so it comes down to how much time you spend in the hardmode caverns watching for a chest that should not be there.