One tip; find some pictures on the Net.
Save them and open in photoshop. Change them to an illustration or line art format by selecting one of the photo effects. Or copy and paste in to MS Word; use the Picture Format tab and select remove background.
Then; resize in inches to what you want. Print out the template in sections with crop lines on 8 x 10 paper so you can tape them together.
I would make it out of green block foam from hobby lobby and use a hot-wire cutting tool you can get pretty cheap. Or just use a knife and some sharp tools.
After that; I would sand it smooth and form it to the shape you want. Install the poles. You may want to add a substrate board at the bottom for extra support. Then wrap it in several layers of fiberglass and resin. Sand it smooth and wallah!
“Every human has four endowments- self awareness, conscience, independent will, & creative imagination.
These give us the ultimate human freedom... The power to choose, to respond, to change.”