Hello RedFeather,
This is an
Alocasia, possibly
A. amazonica. It is a type of the taro plant, the plants that tapioca is made from. Give it well drained soil but keep moist in summer. Give mild fertilizer every two weeks in summer, rest in winter. Do not put it in strong sunlight.
While searching for info about this plant I found
this relative of your plant. Wouldn't you like to grow one that big?!!!