Outlining a model?

Is there any way to outline the models being redered? I have a problem when I’m trying to replace an orginal character in a 2d game with a new one. I’ll show from pics so it’s easier to understand.
The orginal character:
My character:
However when I put it ingame the border blurrings of the image make the character look like it had a halo around it:

Use the “Edge” button on the output tab in the render buttons (F10).