Fold your piece of paper in half, and unfold it again so you are left with a crease down the middle.
Fold the top half of the paper down to the crease, then do the same to the bottom half.
So that it looks like this.
Fold each of the corners into the centre line. This step will make the next step much easier.
This step is more difficult, so I'll try and take it slow. Fold one of the corners out.
Pull the corner outwards.....
...and fold down.
Repeat for each corner.
Fold in half.
Fold the loose corners out to the crease to create legs.
Repeat on each side. As you can see two of the legs are facing the wrong direction....
...so fold both legs on one end so that they face the same way as the others.
Fold the front corner upwards, to make the nose.
And then fold the corner in to make it less pointy.
On the other end fold the corner upward. This will be the tail.
Fold the tip out again.
Add some eyes and you're done! Ta da!!