A traditional origami tried out by many is the frog. It is made from, surprise, surprise, the frog base! And as with most traditional designs, there are numerous sites with instructions on the net on how to make it.
Frogs are best tried out with thin origami paper, since there is a lot of folding involved and a thicker paper will not hold these folds. Try them out with a green paper to make your frogs more realistic :)
Model Details:
Model: Frog
Origin: Traditional
Difficulty Level: Low Intermediate
Paper Ratio: Square
Paper Size: 6 inches
Tutorial: Youtube