vampyre,
I'm not sure if you realize that your question {is too broad } for anyone to give you a realistic answer. If someone tried to answer it the way it is asked the type of response you will get is:
1-> draw the sprite in a graphics package, Mspaint, Paint Shop pro, Photo Shop, the Gimp, etc
2-> make the background color the color you would like to have transparent. (in DBC black is transparent: DBpro Black is transparent by default and cna be changed by <set image colorkey r,g,b>.
3-> save your image to your project folder. Use load <image "filename",imgnum,1> to load your image
4-> Use the <sprite spritenum,x,y,imgnum> comand to create your sprite.
5-> Now write the code that checks to see if your sprite is around an object. (This is the part that is impossible for us to answer unless we know exactly the design and layout of your game. And it's something you need to figure out. If you can't figure this part out, it's unlikely that you will be able to code most of the other parts of a game like this.)
~zen