I am going to guess and say it looks like a non variegated [*Peperomia clusiifolia*,][1] or it could be [*Peperomia claviformis*][2].  I can't decide. 


![Peperomia-Clusiifolia][3]

Peperomia-Clusiifolia 

![Peperomia claviformis][4]

Peperomia claviformis


  [1]: http://davesgarden.com/guides/pf/go/54416/#b
  [2]: http://commons.wikimedia.org/wiki/File:Peperomia_claviformis_1-OB9.jpg
  [3]: https://i.sstatic.net/9qghP.jpg
  [4]: https://i.sstatic.net/70UZr.jpg