In Norse mythology, Andvari (Old Norse "careful one" is a dwarf who lives underneath a waterfall and has the power to change himself into a fish at will. Andvari had a magical ring Andvaranaut, which helped him become wealthy.

Using a net provided by Ran, Loki catches him as a pike and forces him to give up his gold and Andvaranaut. Andvari cursed the stolen gold which would destroy anyone who possessed it. After the deaths of Brynhild and Sigurd, Gunnar left Andvari's gold in a cave. Years later, Andvari discovered the cave and his lost gold, although his ring was lost forever. 

He is willing to choose for you two of his fish, now these are no ordinary fish, they are shifters and can change themselves into dwarves at will. Neat huh?