Honestly I have no idea why so much people voted for the snake.
Those votes have no base. The frog picture is excellent. The wood grain with the moss on the bottom right adds a sweet touch.
Blurry on the top right, the eye travels further down until it reaches the centre. It's redirected towards the frog's eye and zooms out to discover the whole frog in a very impressive picture quality. The details, dirt, mucus on the frog's body are all present. The light on its back giving a small shadow makes the eye travel further don to the right and discover the wood grain and rotten part. Some light blurry moss sitting on the bottom of that wooden cliff add a very nice touch.
From further away and globally, the picture has 3 parts: The frog, the wood details on the bottom right, and the very rotten wood plank going diagonally on the top right. However, the frog, the main point of the picture, still occupies 2/3rd of the canvas. It's off-centered towards the bottom left, following the rule of thirds.
The game of shadows with the wood is impressive, with very bright light on some parts almost becoming white, and absolute darkness on the miniature moss cliff and in-between the planks.
Good luck in your contest, and please submit the frog. With maybe a bit of a more artistic title ^^ not just 'The Frog'.