A trusty, helpful Golden Retriever which shape-shifts into anything you could dream of. However, it affects its foes because whenever it barks it makes them deaf.
A mystical map. If I wanted to go anywhere I would wish for it to teleport me speedily there when I said “please send me to this distant place”.
A bottle of healing water. When you drink one single refreshing drop it instantly heals you so that you feel like a mighty God.
I would take a small tent to act as a cosy shelter. When you go inside this magical, terrific tent it is like the size of a house with several amazing rooms. One would include a bulky, bouncy triple bunkbed.
I would bring a small silk bag that you could fit in whatever you desired, but it would still not be full.