step 1 of 5
Made the canvas larger by adding a mirror-copy of the left-side.
step 2 of 5
Used the channels to create a mask for the animal.
step 3 of 5
Made a copy of the animal. Changed them with the liquify-tool. Used cut- and paste to turn and replace the heads and the paws.
step 4 of 5
Erased the animal.
Used cloning tool to fill up the background.
step 5 of 5
Put the animals in place, fixed the bottom with cloning tool.
Still some work on the paws needed...