Oh you don't have to >w<
I just love drawing them!
I have my own mask like characters, and I love drawing expressions for them XD (Half are that their mask can move and make expressions, half can't)
I have one and his name is Rodrick Boones, he's a skeleton. and his expressions are funny to draw.
"Well well what have we here." A man with huge horns on his head steps out arms crossed as he smirked softly his demon ears pointed and his tail simply curled up. " A demon pawn working for me in my mists , please call me Lucifer. But I am sure from a distant a mere mortal can figure that out.... " Lucifer held out his hand to the other with a sure smile as he chuckled softly fire coming out of his nose.