Unknown plant from unknown (big) seed

[TheIbsanos]

Hey,

So we took over a bigger plant and in its pot another type of plant started shooting from what looked like small avocado seed put in there, laying on the top of the soil.
Do anyone have any idea of what this plant could be?

 

[cpp gardener]

Has anybody told you it's a potato? Or did you figure that out yourself?

 

[Catalog of Plants]

very similar to potatoes