It's kind of difficult to figure....I personally like somthing menacing with my monsters, but I feel the look of the creature is more important when they are more human in size than if they are 200 feet tall....
(IMO WARNING) I kind of look at it like this....wether Godzilla looked like he did in TOMG or he looks like the 1984 version after it crushes the super X, a 200 foot Barney with bad intentions and some invinvibility would cause damage and be frightning....hell the Stay Puff Marshmellow man looked all cuddly till the monster in it came out.....people will be scared and run....Now I would like the creature to be menacing and fresh, but it doesn't have to visually scare me, just what it is capable of...
Scale it down to human size and the look is much more important because the damage will be caused in a much smaller scale.
LOL, watch it have Gigan "Hands" Megalon wings, 2 Ghidorah tails and the face of Gabbra.....UUUUGGGGLLLYYY!!!

You must show no mercy, nor have any belief whatsoever in how others judge you... for your greatness will silence them all!