So, a couple of things.
Orange: There are stray pixels here.
Blue: There needs to be shading here.
Red: This part uses a different skin color than the rest of the mug.
Magenta:These parts have pixels that don't belong.
Yellow: The shading here is wrong
I'll elaborate a bit on the shading thingy using the line examples I put above.
So, right now the way you shaded those parts is a bit like number 1, where the shade is the same length as the outline. It should be something more like two or three. Two is an example of anti-aliasing with two colors (think of the white backround as the first color) and 3 is how it should be done with three colors. If you would like, I could demonstrate how it should be done on your mug.
All in all, they are pretty minor issues and it's not a bad splice.
Though, the hair is a bit weird, but I'm too lazy to comment on it.:p