I think it was suppose to represent the evil around Ciel. So maybe it does represent Sebastian, but I like to believe it's not because Sebastian is too hot to be that scary looking thing. （￣へ￣）
wow when did sebastian get so ugly
That's the Jabberwocky, from Through the Looking-Glass, and What Alice Found There (Lewis Carroll's sequel to his most famous novel Alice in Wonderland). It's a scary monster described in a poem there. Probably just a way Violet uses as a metaphor for Ciel's danger (as in danger for them, since he's asking dangerous questions).
Look, the original Jabberwocky is this one: http://www.writeraccess.com/blog/wp-content/uploads/2014/05/lewis-carroll-jabberwocky.jpg (=・ω・=)
Wow I didn't even think about the Jabberwocky haha!
I am glad that is not what Sebastian actually looks like (⌒▽⌒)
no I think it's supposed to be something evil or dark in ceil
http://www.mangago.zone/read-manga/kuroshitsuji/an/kuroshitsuji-chapter-73.html/9/
Do you think the creature in the drawing on this page is suppose to be Sebastion?