Fold the piece of paper into halves along its longest axis

Unfold it.. Grab one corner and make a triangle making sure it's edge is on the line of fold you just made in step 1

Do the same to the other corner..

Now fold the big triangle along its base..

Cut the paper following the fold you just made along its base.. Using a ruler can be handy..

Now.. You have a big triangle.. Unfold it.. Make a triangle with its base opposite to the previous one..

Grab the corner and fold it..

Grab the other corner and fold it.. And this is the 2nd triangle..

When unfolded you should have a piece of paper shaped like a big rectangle divided into two equal squares.. Each square is devised into 4 triangles..

Now a tricky part.. Grab the middle of the base of two opposing triangle on the side of one square..

Make the middle touch each other.. Use two hands for each side (I'm using the other hand to hold the iPad ;) )

If you did the previous step correctly.. You will have converted one of the squares into a triangle..

Beautiful.. Isn't it? Now let us do the same to the other square..

Like this! The two squares are now two triangles.. It will look like two layers of triangle on top of each other.. (The doted line is drawn for the next step..)

You saw where the dotted line.. Fold along its axis..

Fold the other corner the same..

Make it the same arrangement to the other half..

Nice.. All four legs-to-be are in position..

Fold each "leg" into halves along its long axis..

Do it to the other leg..

Flip it on its "tommy".. Now, how about that?! You see a diamond on for legs.. I will choose this side as the head with its two frontal legs.. You will see what I mean..

Fold the diamond along the "long" axis to shape the head-to-be

Fold the other side.. Now you are seeing it!!

Now.. Another tricky part.. Approach the "rear".. Fold the diamond corner and hide the corner beneath the flaps you have just made in the previous step to make the head.

Like this..

Flip your frog on its back..and fold into halves.. Make the rear legs touch the front legs..

Now fold the rear-legs-part into half making the legs point into the opposite direction..

Press along the line of folds to make it neat.. Look where is my thumb is pressing.. There should be the spring mechanism to make the frog jump :)

Here is your frog.. You can call it any name you want..