BriannnD
Dreams come in many shapes. It all depends on what that particular dream is, but, the undeniable truth behind dreams is that they all share a common shape, that of which, is a marble.
But, dreams don't usually take physical shapes, and normal humans would never be able to see them anyway.
However, on the off chance that a dream does take physical shape, that can only mean that one thing has happened; a dream has been shattered. Those shattered dreams are left to wander the earth until they are picked up by the one who was created to collect shattered dreams.