The elephant has a background that needs to be erased.
1/. Create a new transparent file using the exact same dimensions of the elephant (your foreground image).
2/. Then copy/paste the original image to the transparent background.
3/. Then using the Magic Wand Tool select the background and the Eraser to remove the background. If there is any background left you need to select it and erase it. Ensure the background is clear of 'debris', as this will show up on the background image.
There are several other tools you may need to 'clean up' the background.
4/. Make a decision about the sizing of the foreground and Image Adjustments/ Image/Size and downsize the image if necessary.
5/. Save the image as either a CompuServe Gif. or a .PNG file. This will give you the clear background you need.
6/. Close the original .JPG image and open the new transparent background image, then copy paste to the background.