Soppy the Shadow Monster
Of course, I've patterned the title after many common muppet names.
The way I imagine it... Although ol' "Soppy the Shadow Monster" looks scary, he's actually a bit insecure. Also, being a kindly soul, he goes to great lengths to avoid scaring people. And it upsets him terribly when he does anyway.
So, please, kids, don't be afraid of him.