While I am not sure “reclining grass people” were created, seems to me that you could  buy used mannequins for this project. We have lots of distressed and cheap mannequins in our “mannequin boneyard” (available to SF Bay Area customers only.

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photo by http://www.flickr.com/photos/jamilascott

For more ideas on using mannequins in the garden, see our Pinterst board  on garden and flower shop displays.