This one is actually much more simple than it appears. It just takes some time and patience. Learning to roll the legs up just right can take a little practice. The only other downfall is it requires five bills so it's a rather large chunk of change to include along with your normal tip.

Difficulty : Beginner-Intermediate
Number of Bills : 5
Denomination Recommended : Any
Credits : Money Origami

Diagram [PDF]

Front Angle
Spider 01-01
Front
Spider 01-02
Top
Spider 01-03