The 3/4 view drawing is looking pretty well.. The only things I
see is the ears are shifted a bit to far to the characters
right, and the right ear is little too far forward.
You could just leave the left ear alone and move
the right ear back and to the left a bit.
The hair should look better after the ears are shifted
to the left a bit. Otherwise the hair design looks good.
Unless your going for more of a toon design the muzzle
is really too small for a mouse . A mouse head is a lot
like a rabbit, just more pointed.
Another thing study the things that make a mouse
look like a mouse. In toon designs it's always helpful
to exaggerate things a character is known for just a bit.
The head by it's self might be part of why it's not looking
quite like a mouse. Sometimes you need the whole character
to get the look your wanting. skinny tail and all.
If I may. I suggest looking online for a picture of Stuart Little.
This is a cute design of a humanoid mouse. You might not want
it to use this character style, but the design has a good mouse face.
The following link has several pictures and cartoon renditions of
the character which can be very helpful in designing your
own character.
http://images.search.yahoo.com/search/images;_ylt=A0oG7ljMNDZRiz8ADbdXNyoA?p=stuart+little&fr=moz35&fr2=piv-webOver all your doing good with the 3/4 view
Getting everything lined up takes practice, but
your getting there.
Keep up the good work.
Old Rabbit