I found these cute monster cupcakes on CakeCentral.

They are made by Jennifer and she told me that she has used buttercream icing and Wilton tip #233 (grass/fur) to make the little furry cupcake monsters. The eyes are also buttercream icing and are made by using Wilton tip #12 (round) and the pupils with Wilton tip #2 (round).

I think they would be perfect for a space-themed birthday party, or maybe just for fun?

Happy Caking!