Summarize:

Stick the feet to the bottom of your duct tape circle.
Make a square of duct tape cloth. Scribe a circle on one side, using either a compass or by tracing a round object that's the size you would like your turtle's shell to be. Fold a length of tape from end to end, leaving a flap of sticky area at one end. Cut the folded tape in half lengthwise. Round the folded ends with scissors to make "feet". Repeat for "hind legs". Attach googly eyes to the head of the turtle if desired.