For my son's 5th birthday he wanted a "butterfly" party. It was a little difficult finding butterfly party-wear that was not "girlish"(his description!).  We used a butterfly rubber stamper to decorate paper plates (outer rim, only), napkins, cups and goodie bags (brown paper lunch bags). I found inexpensive butterfly net's, plastic butterflies, plastic butterfly hair ornament (which were used as pins to be clipped on child's shirt),butterfly stickers that were put on whistles, butterfly glider (planes) all at the dollar store!  We cut out butterfly silhouettes on different color construction paper.  We also found a local woodcarving group who ,for a nominal fee, die cut wooden butterflies. Each child was given a butterfly tattoo in the "butterfly hut" (an easy fold up playhouse), when they first arrived. The children started out decorating their wooden butterflies with washable markers (a Popsicle stick was glued to opposite side for use as a garden/plant decoration.)  Next they participated in a butterfly hunt using their nets to find a designated amount of the plastic butterflies that were hidden in the yard. They then used their nets again to "catch" construction paper butterflies that were gently tossed in air (aiming at their nets!) After both games they received prizes (butterfly hair ornament on their shirt and whistle with butterfly sticker on it). Butterfly piñata was next followed by cake, gifts and goodie bags which consisted of all the things each child accumulated over the course of the party in addition to butterfly glider and a "metamorphosis" coloring booklet we made up with info off of the internet. The kids had a blast and so did we!