I made this Gumby cake for my little sister's 22nd birthday. She is a big Gumby fan but I couldn't find any cakes on your site. I found a template on the internet and enlarged it. I started with a 9x13 box white cake mix. After it cooled I put the Gumby template on top and cut around it.
Then I used store bought white icing colored with Wilton gels. I used a star tip for most of the cake then a thin tip for the mouth, eyes and nose. I outlined the cake with the thin tip. My sister was so happy with the cake she didn't want to cut it!