I am not sure what graphics program you are using.
With Paint Shop Pro or Adobe Photoshop you use the layer option.
You open the icon or the plaque as 1 image, then open the animal image you want to use as another image.
Use the edit cut comand on the animal image, toggle to the icon or plaque image and then use edit paste as new layer. Then use the move tool to move tha anumal layer around to find the look you want the icon or plaque to have.
Then go to the layer tool again and merge the layers to form a single merged image and save in PNG format.