Hey all,
Inspired by the competition we're currently running
here (closing date Sept. 30th) and the site
Human Descent I decided to gave it a try and entered with the following image:
(click for a bigger version)Actually it was my 2nd entry, but the first one was too crappy to make a tutorial on it, so here we go!
First of all look for some quality images, where the two heads are positioned more or less the same. Ofcourse you can always resize and turn it a bit, but the angle should be more or less the same.
I came up with these images:
Snake by Matt BrockiCrocodile by Meezer

First of all thank you for putting these images on
SXC, and for the members please take note that the snake image is free but only for
non-commercial work, like my tut
If you want to look for other images, check our
links section, where we posted lots of valuable links to stock databases like sxc
Ok, here we go!
------------------------
Open your two images in photoshop and select the image with the head you want to paste on the body of the other animal. Therefore, I select the croc-image.
Select a tool of your choice, I prefer the
Polygonal Lasso Tool over the
Magnetic Lasso Tool, but that's a matter of preference.
Cut out the part of the head you want to paste on the snake. Once done
Ctrl+C and go to the image of the snake.
Paste it in the snake image (it will be in a
new layer, on top of the snake). Now
rotate and
resize it until it fits perfectly on the snake, thereby covering the snake's head. Easy because now you dont have to erase that part! Because we need to attract the viewer's focus to the head (since that is what we adjusted..) it's no problem if the head is slightly bigger, just try and see what comforts you.
Now,
Ctrl+click on the top layer (croc), now you see it automatically selects the head only in that layer.
Go to
Select -> Feather and choose a value, I picked 2. While the top layer is still selected click on
Add Layer Mask.

Now, the biggest problem is ofcourse the skin. How on earth can you make the croc's head look like the snake, and at the same time keep the croc's shape, teeth, eyes and mouth?!
Simple!
Select the
Clone Stamp Tool and start cloning!
Because you gave the Croc Layer a mask, you can never go out of its boundaries, thereby reshaping it's head. Thats one.
In order to keep the eye, mouth, teeth (and pattern), you have to play with the
settings of your brush and opacity.
I used a brush with
80% hardness.
For the left side, it's important that the two images/layers blend in nicely, so I used a high
opacity (100%). When moving to the right, I lowered it to around 50%. If you then move over it again it becomes darker, and you can stop at the point where you think its perfect!
Now about the clone tool:
The clone tool first needs a
starting point. You do this by selecting the bottom layer (snake) and
holding Alt while clicking. Make sure you select a good starting point, where the area around it is identical and there is enough space. I selected this area:

As you can see the mouse pointer changes in a
crosshair. When clicked select the top layer (croc) and decide where you start.
Now if you start cloning, just hold your mouse-button pressed and slowly move around. There are
2 pointers! One is where your mouse is positioned and where the croc's skin is changing into a snake. The other one is where you alt+clicked the bottom layer. You can now see thet that one moves along, so if you hold your mouse button and move to the right, it copies the snake's skin on the right of where you alt+clicked.
This makes sure the pattern is completely copied! This makes it important to watch the left pointer (on the snake's skin) because if you move to high or too low, it might copy the background, as you moved out of the snake's body.
Don't you just love the clone tool?
(click for a bigger version)